To convert comments from Stan Rogers and Oddthinking into an Answer:
Camphor and methyl salicylate (the chemical that gives wintergreen its characteristic aroma) are both ingredients in actual working over-the-counter topical analgesics like Rub A535. The camphor is an irritant, acting in a way similar to capsaicin. Methyl salicylate is an analgesic similar to aspirin, but it's usually used in relatively higher concentrations (10-20% of the preparation by weight).
Contributor Oddthinking has drawn attention to Extractum Belladonnae Liquidum, which is known in Western medicine as simply Belladonna. Belladonna is a plant; its leaf and root are used to make medicine that interacts with people's nervous system. The U.S. Library of Medicine says that belladonna can be poisonous; for this reason:
Since 2010, the FDA has been cracking down on homeopathic infant teething tablets and gels. These products may contain inaccurate doses of belladonna. Serious side effects including seizures, breathing problems, tiredness, constipation, difficulty urinating, and agitation have been reported in infants taking these products.
Though widely regarded as unsafe, belladonna is taken by mouth as a sedative, to stop bronchial spasms in asthma and whooping cough, and as a cold and hay fever remedy. It is also used for Parkinson's disease, colic, inflammatory bowel disease, motion sickness, and as a painkiller.
Belladonna is used in ointments that are applied to the skin for joint pain, pain along the sciatic nerve, and general nerve pain. Belladonna is also used in plasters (medicine-filled gauze applied to the skin) for mental disorders, a behavior disorder that involves hyperactivity and inability to concentrate, excessive sweating, and asthma.
Belladonna is LIKELY UNSAFE when taken by mouth in adults and children. It contains chemicals that can be toxic.
Side effects of belladonna result from its effects on the body's nervous system. Symptoms include dry mouth, enlarged pupils, blurred vision, red dry skin, fever, fast heartbeat, inability to urinate or sweat, hallucinations, spasms, mental problems, convulsions, coma, and others.
That article has warnings against using belladonna if you are pregnant or breast-feeding, suffer congestive heart failure, have constipation, have Down syndrome, have esophageal reflux, fever, stomach ulcers, gastrointestinal tract infections, gastrointestinal tract blockage, hiatal hernia, high blood pressure, narrow-angle glaucoma, psychiatric disorders, rapid heartbeat, ulcerative colitis, have difficulty urinating, or are using other drugs.
Do not use Belladonna after reading this Answer without consulting your doctor and/or reading reliable up-to-date health information that you trust, such as from your health organization or the government.