After doing 1 arm swings with the 48 kg bell yesterday at my house, I have highly considered buying liquid chalk so it doesn't make a mess or I don't destroy my TV with the bell flying out of my hand. While I don't have any grip issues or didn't have any issues yesterday swinging The Beast I could certainly see where if you were going to try and achieve Sinister (or Simple) and get the swings done in under 5 minutes chalk would be helpful. If you are worried chalk is cheating then don't use it and go about your business. Or if you are worried you aren't getting the necessary grip work then don't chalk up during your training sessions and save it for the timed / test days. Go about achieving your goals in a way that will make you feel proud about what you have accomplished.