There's no perfect way that I have found. Harsh chemicals like lacquer thinner and carb cleaner will clean them quickly and easily but will soften the wheel so much it only makes the problem worse. I run a couple sport steering wheels and what I do is clean them with a soapy vinyl or dash cleaner. It takes a lot of scrubbing and is hard to get perfectly clean, then I use a vinyl protectant that may make it feel a little slick, then wipe it with a clean rag again. Depending on use, (the more the better) it will feel more natural. It is just the nature of the material though. Heat magnifies the problem. It's just age and ozone. I'm still looking for the perfect solution.