whoa old thread. There was a big hoopla sometime ago where the otc Zymol stuff wasn't really Zymol/same company. Can't remember the specifics. I do remember trying the otc Zymol qd'er and it was crap.
If you have to go OTC, Lexol and Blue Magic are your best bets. I like Blue Magic more than Lexol. Think I found it at Discount Autoparts? Their leather/vinyl cleaner and conditioner is excellent. So if you need otc go that route, otherwise, plenty of excellent boutique products for around same price and a little more here.