That White Creamy GO-JO hand cleaner is an excellent rubber cleaner/conditioner. Rub it on with your hand and wipe it off with a towel. It leaves the rubber clean and soft. Pep Boys has it.
I would avoid using petroleum products as they can degrade the rubber/plastic. I treat them with a light coating of silicone spray. Keeps them clean and the rubber nice and soft.
I had the same question when I purchased my first rubber handle snapon ratchet. I work on filthy equipment with agricultural chemicals,to diesel and so on. I have had other brand name rubber handles crumble apart. The snapon handles are holding up great. I wipe them down clean when done and no problems.
I would avoid using petroleum products as they can degrade the rubber/plastic. I treat them with a light coating of silicone spray. Keeps them clean and the rubber nice and soft.
Yes, I found ATF to be the worst. Once left a greasy ratchet coated in ATF, came back to use it a couple weeks later and the rubber swelled up. Had it replaced but now I give them a quick wipe after use and they still look new.