I am a veterinarian, and I would advise you only use Frontline or advantage. Stay away from the hartz brand and other over the counter flea medications, esp. for cats. The other products usually contain permethrin or like chemicals that can really be bad for cats. I have seen a lot of reactions to those products. Fronline is fipronil, and advantage is imdacloprid which are much safer and over the counter now. Revolution is also a wonderful product, but you can only get that from a veterinarian. You want to always use the one labeled for cats and the dose is based on weight. Also, for shampoo I would just recommend a mild shampoo that is labeled for cats. I wouldn't use a flea or tick shampoo on a cat. Also, if you are bringing him inside to live with your family you should have a stool sample checked for intestinal parasites and get him vaccinated just in case!! Let me know if you have any questions!