Apparently, the hottest new trend in massage is meat cleaver massages.
That's where you lie down and a masseuse whacks your back with two dull meat cleavers over and over. Apparently it feels good and there's some spiritual "energy" stuff involved in the process.
You have a towel over you, so it's not blade-on-skin, and the cleavers are dull but still. The massages have been popular in Taiwan for quite a while, but lately, they've been popping up all over the world. The most popular spot for these massages in Taiwan says they've never had a client injured in their 40-year history.