Originally Posted by
oeoeo327
The other option I've seen work fairly well is using lanolin-based hand cleaner (without pumice, of course). Both options will work, providing grip and keeping odor to a minimum.
I've never owned foam tires, but have used GoJo hand cleaner (with lanolin and glycerin) on r/c rubber tires and it does soften them nicely. And it cleans your hands instead of making them filthy.