A guy at a flying club was renovating an old, slow glider and was proud to have sourced a (cheap) handlebar grip from a bicycle shop for his control stick, instead of the original and expensive grip. So we gave him a pushbike bell to go with the grip. He actually put it on for a few days and used it to summon the tip walkers when he wanted to take-off. After a few days the novelty wore off though.