They hold up well & won't disappear like wax. I have one on my creek paddle (just the power hand), and they're the only thing I found that works well with or without gloves. I've also inserted a thin strip of foam under the middle knuckles for some home-made indexing. They usually hold up to a few seasons, so one pair will probably last the life of the paddle, if you just place one only on the power hand.
Manly chest; free-of charge with purchase: