Bitter Apple is a product commonly used by pet owners to ward off unwanted behaviors, primarily chewing. Margaret Reister, DVM, Ask the Vet columnist, describes Bitter Apple as nasty-tasting but benign.
"In the veterinary clinic, we use Bitter Apple to keep animals from chewing on their bandages," she says. "It is mostly made of inert ingredients with a small percentage of bitter principles to give it that awful taste." Bitter Apple is available in pet stores.
Dr. Reister notes that Bitter Apple doesn't last long and needs to be reapplied frequently. She also believes that for couch chewing, Tabasco sauce might be a better choice. "From what I've heard, Tabasco works better than Bitter Apple in discouraging chewing on furniture." She recommends doing a patch test with the Tabasco to make sure it won't stain your furniture.