Audio Research soft touch switches, how do you clean them

These seem to have a printed circuit under the soft rubber covering, the same as most Audio Research remotes.....Of course you can't use a strong solvent ??  Have you ever cleaned one ??        Thanks
I use a pencil eraser (lightly) on both the metal and the rubber pad.  I treat the metal contact with Caig ProGold on a Q-tip.  works for me.