A little bit now and then isn't bad for them. Some people even use petroleum jelly for hairballs instead of the hairball remedy you can buy. However, like anything, I would think if he ate too much of it at once it might upset his tummy. Sneaking up on your wife and stealing a few licks wouldn't hurt him, but you might want to put the container in a cupboard or medicine cabinet that he can't get into. I'm almost positive if he ate the whole container in one sitting you might have problems.

Welcome to PT! I see you're tuxie kitty - what's his/her name? But I don't see any orange fuzzy/comfort kitty.....