Any petroleum-based oil will break down the rubberization and make it eazier to peel off. Wipe it down with some leave it a thin coat on it for about 15 minutes, wash the oil off, then try again with the dental picks if you're having difficulty.
This goes for everything rubber-based. Back when I played paintball, we had to make sure we used a non-petroleum based oil to lubricate our guns. If you used wd40, it would break down the O-rings that sealed the high pressure air, and you'd have a leaky gun... have to replace all the damn orings.