So simple green is OK. Not ground breaking but it helped. It still feels kinda like it leaves residue on your hands but not really...
So it helped.
I'd spray with a product like 303 Protectant to coat and replenish the oils that are, obviously, being baked out of it by the sun.Even Windex might provide a protective coating. Sure seems like it couldn't hurt to try it. I'd sure try coating it with something to seal it. YMMV