Please read my previous post.

If you want your cork to retain its good looks, then definitely, use a sealer on it.  If you want its appearance unchanged, use U40.  One coat only.  Then, when it gets dirty, you can easily wash it to return it to (almost) its new appearance.

Alternative? I use Duck Brand Wrap-Fix Self-Fusing Silicone, $5 at Walmart. One roll wraps three 7 ft rod handles with some left over. Wipes down easy. The cork underneath has literally never been touched. The plastic wrap is still on it. I personally like the look and feel. Different strokes for different folks. It's more sturdy than a tennis grip wrap because it fuses to itself. It's used for low pressure water repairs so for all intents and purposes it is waterproof.