Just wanted to chime in, since I'm a soaper. Anything sold as "soap" in the US is alkaline and made from Sodium Hydroxide (Lye) or Potassium Hydroxide (Potash) mixed with fats and oils. Dish detergents are also alkaline and made up of chemical agents and surfactants, like Sodium Lauryl Sulfate. Soap can be "superfatted" like castille (full olive oil soap) or homemade soaps; and contain free oils and glycerine produced from the soapmaking process. Detergents can be alkaline (Dawn, Ivory, Tide) and use surfactants to "pull" away dirt and oil; or they can be acidic (usually reserved for industrial purposes), and clean by eating away proteins and vegetable matter--which would cause leather to breakdown.
The pH of leather is around 5, white vinegar is around 2.5, water is around 7 (neutral), Ivory is around 7.6, Castille is around 8.0 (depending upon who made it) and Simple Green is about 9.6. A low alkaline soap diluted in water shouldn't be a problem. IMHO, dilute castille or homemade soap is probably your best bet for gently cleaning leather, because of their free oils.
As for Leather CPR, their claim to only contain "cosmetic grade" materials irked me--because they never disclosed these "skin-safe" ingredients. So, I did some digging and got an MSDS--which did not disclose any ingredients, but did list the parent company--Ambiance Cosmetics. Ambiance makes a "Transforming Cleanser" for the face that looks a lot like Leather CPR. I would venture a guess that the products contain the same things, maybe with a formula adjustment and lanolin added to Leather CPR. However, exactly what those ingredients are still remains a mystery. They would only admit to "a super blend of hydrating avocado, macadamia, olive and jojoba oils, with Omega Plus - the ultimate antioxidant protection, along with natural emulsifiers". And because the product is "cosmetic grade" they are not regulated by the FDA and aren't required to disclose the ingredients when used in industrial applications--unless it is reactive or flammable. We may never know the truth.
(I really think they stole the formula for Cetaphil; hence, the secrecy.)
Thanks for the info StarBrown! I hope if they did steal Cetaphil's formula that they kept the parabens out. I remember reading some forums of people complaining their leather cpr went bad after not using it for a long time, so that's probably a positive if that means no parabens
