I don't think the feline chews have chlorhexidine.
From my limited sample (5-6 cats), the fish-flavored chews seem to be more popular. My cat can't tolerate the poultry ones, they seem to make her queasy (she'll try one, throw it right back up, and won't touch another one after that...I have tried them a few times, but it HAS to be the fish flavor)...and the cats I've tried to pawn the leftover poultry ones off on have been lukewarm, as well. Go figure.
I just use one a day, though dental-chew-time is eagerly awaited. Assumpta flings herself halfway up the cupboard (she looks like one of those Garfield suction-cup-window thingies), meowing at the top of her lungs, whacking at my ankles until I can get the jar open and get the chew out. I have to toss them into the bowl, because she will chew my arm off trying to get to them.