Colloidal chemistry – as they are using it – means detergent. As you surmised, Their cleaning system is a spray bottle, an unremarkable detergent mixture consisting largely of water, and elbow grease.
This product is an excellent example of how detergent manufacturers put lipstick on a pig. More generally, it's a lesson about how experts in marketing and public relations take advantage of the way we think.
My answer is based on my own professional experience as a manager of a business that manufactures cleaning compounds. As you read this, note that I am not criticizing the manufacture of an unremarkable detergent product that contains chemicals, i.e., my own livelihood. I am using my insider knowledge to show where the marketing material is misleading, and, more generally, how the public's basic honest and cooperative nature becomes the tool of the P.R. expert.
In normal social situations, most people will assume automatically that what you say is: (1) provable, (2) complete, (3) relevant, and (4) unambiguous. This is the cooperative principle. The cooperative principle is well known to experts in marketing and public relations. They violate it deliberately in ways they do not intend you to notice, so that you will not become skeptical when you are evaluating what they say.
With that in mind, let's unpack the product.
The most obvious clue to the nature of this product is this quotation from their FAQ:
Q - I found I needed to scrub very hard the first time I used ECO MIST PROFESSIONAL CALCIUM & LIME. Why is this?
A - Initially, tough calcium and lime jobs may require vigorous scrubbing with a good scrub pad to remove previous chemical build-up prior to removing the calcium and lime deposits.
While you vigorously scrub away the "previous chemical build-up", note that the term violates unambiguous. The cooperative person is intended to think it refers to "toxic" cleaners used in the past, but it means "soap scum". That's actually the manufacturer admitting that you are cleaning the surface by scrubbing it with a pad.
The terms "agricultural ingredients" and "colloidal", and the images of coconuts, grain, an ear of corn, a tree, a potato, a soybean pod, sugar cane, and grass, violate complete and unambiguous. The manufacture has not simply ground up bits of plants, suspended them in water, and by some scientific miracle created a "powerful, industrial-strength cleaner". The safety data sheet identifies the pH as 10.4, which is highly alkaline. It is alkaline enough to dissolve organic matter: comparable in pH to the wash water in your laundry machine. This is not a property of ground-up vegetables.
It is, however, a property of chemicals commonly used in detergents: synthetic surfactants and alkali metal salts that they can include in the product while simultaneously implying that their product is free of them. Note that they warn you to rinse the product away after cleaning the surface. This is so that you or your food do not come in contact with these chemicals.
Did you notice that the picture of the coconut actually represents processed coconut extract (not coconuts) or that the picture of the soybean pod actually represents soy (not soybeans)? The cooperative person isn't supposed to notice. Processed extracts of agricultural products include some dangerous chemicals. Processed coconut extract in the form of coconut oil reacted with diethanolamine is called cocamide diethanolamine, a highly alkaline surfactant. Similarly, soy oil reacted with diethanolamine is called soyamide diethanolamine, and soy oil reacted with methanol is called soy methyl ester, or soy biodiesel. These chemicals are commonly used as solvents in household and industrial cleaning products.
The claims "without harmful ingredients" and "non-toxic and/or food surface safe" violate complete and unambiguous because these are technical and legal terms, and few people know what the manufacturer is actually claiming when they are stated without an explanation. Many detergent ingredients, including harmful or toxic ingredients, can be legally treated as not harmful and non-toxic depending on the amount found in the product. An ounce of a harmful ingredient may not have to be disclosed as an ingredient at all, when it is mixed with more than three quarts of other substances, such as water. It depends on the ingredient, but many common detergent ingredients fall into this category.
The manufacturer identifies water as an ingredient, but fails to identify the quantity, and so violates complete. Water is plainly a big part of this product. The safety data sheet gives several properties of the contents which identify it as mostly water: specific gravity 1.001, freezes at 28 °F, boils at 214.40 °F, flashpoint >200.0 °F. So we know that much of the price of this product is the freight cost to move the manufacturer's local water supply across the country to you.
They claim that USDA certifies at least 25% of their ingredients to be renewable biologicals. Then they claim that 75% of their ingredients are biological. This violates unambiguous. First, the cooperative person assumes they mean 75% of their ingredients are renewable biologicals, but that's not what they said. Petrochemicals are non-renewable biologicals and they are used a lot in cleaning compounds. 50% of their ingredients could be petrochemical without making their statements false. Second, the cooperative person takes away the message these big percentages imply, that there are a lot of biological ingredients in the product, i.e., it contains a lot of active ingredients. But we know that most of the product is water, and this is either not being counted as an ingredient or it's being counted as a "biological ingredient".
"Colloidal chemistry" suggests there are suspended bits of grass, potato, and so on in the product. While that may be true, their description of it violates complete, relevant, and unambiguous. "The ability to create billions & billions of charged particles from agricultural ingredients that can penetrate surfaces to a depth of a nano-meter (1 billionth of a meter) and lift, suspend and emulsify oils making them 'readily' biodegradable" is nothing more than a description of a chemical surfactant.
A surfactant has a charge on one side that attracts a particle of oil, and a charge on the other side that attracts water. The bit of oil gets picked up by the surfactant and suspended in the water as a colloid. That "colloidal chemistry" is common to any unremarkable detergent on the planet, and has nothing to do with the bits of potato they might put in their mix tank to create their so-called colloidal product.
Some of the quotation is misleading by irrelevance. "Billions & billions" is an irrelevant number. "1 billionth of a meter" is an irrelevant number. Penetrating to a depth of a nanometer means it doesn't penetrate an oil stain: it operates on the surface. Don't those big numbers sound impressive, though?
In short, the manufacturer's claims leave the cooperative person with a very misleading impression. Instead of being chock-full of potatoes and corn and tree sap (which I wouldn't want to spread on my bathtub, thank you very much), the product is a dilute detergent, most likely featuring cocamide diethanolamine and other ingredients such as alkali metal salts, with maybe a little potato and corn starch thrown in to let the marketing department go to town.