some products like bleach or white vinegar will burn the cats feet and their tongues and throats, when they then lick their feet.
it is best to use hot soapy water and laundry detergent, cleaning up the soap after with clear water.
there are numerous opportunist organisms which infect cats, i mean the worms, of which there are about 5-major kinds. the vet has two "worming" options, to use drops or pills. my cats get drops, since they are always eating fleas and getting tape worms, but they have a negative reaction to my forcing them to swallowing a pill, and that depends on whether the cat is easy to handle or not.
the vet uses a stool sample and runs a diagnostic under the microscope , called a fecal, then treats for the worm eggs present. however, a broad spectrum wormer is usually used.