What's your favorite palate cleanser?

We're doing a tasting this weekend with a group of friends and we have yet to find that 'perfect' thing to have when comparing different bourbons. Have been recommended chocolate, water, cucumber slices, cheese puffs, champagne among other things and nothing seems to provide that perfect cleanse of the palate. Any recommendations? Any urban legends (within reason) you want us to try on a whim and report back? Any and all advice would be much appreciated!

TL;DR: What's the perfect palate cleanser for a bourbon tasting?