We had a friend who would play Metal when the ice cream store he worked at was closed but the customers were lingering too long. It generally worked, as he was immune.
Most Japanese know it as "the closing song"
The goal wasn’t to offend or clear out 100% of the customers - just make a large enough portion decide that outside might be more comfortable/conducive than inside. The 20 or so customers who were fine with the cacophony were easy enough to wrangle manually, and also generally either people we knew well .