Dorodango is the art of making shiny mud spheres, such as these:
To make a dorodango, you collect a core of dirt (optionally mixing in color powder), mold it into a sphere, and then rub it with progressively finer dirt in order to dry it out, until by the end you're rubbing it with dust. When no more dust will cling to the surface, you rub it gently with a cloth to polish it, and it's done. Various sources indicate that it takes a couple days to a week to complete (that is, dry) a traditional dorodango.
If you don't want to wait a week for your dirt to dry, you can speed up the process by using a refrigerator. Wrap the dorodango in a plastic bag, put it in the fridge, and it will increase the rate of condensation, supposedly.
However, Wikipedia says that for water to evaporate faster, you need higher temperatures and lower pressures. In a fridge, you have lower temperatures and higher pressures (due to cold air being denser).
My guess is that the actual effect of cooling off the dorodango is that the mud contracts due to the lower temperature, which squeezes more water out of the core and toward the surface. I can't find any dorodango sources that mention this, though - they just say that a fridge increases the rate of condensation.
Does putting a dorodango into the fridge change the rate of condensation, or does it just force the dirt to compress more?