I have white cork bar tape. It comes pretty clean with a damp sponge and dishwashing liquid. It comes perfectly clean with a damp sponge and octagon soap! A friend gave me a bar of octagon soap, and I don't know much about it, but I think it's been around since the dawn of time, and it works like a champ.

I found a link:
http://www.americarx.com/Products/12707.html

It's excellent stuff. Probably your great-grandma used it.