The un-shellaced grips get dirty very quickly, but they clean right up with something like 409. The advantage of cork is that it's not slippery when wet. That's why it's used on fishing pole grips. You lose that if you shellac.

I've been experimenting with staining cork grips to match my saddles like on this one:



I think I see a similarity between that bike and yours. I wonder if we've both been influnced by the bikes on Chris Kulczycki's site?