I've heard of pro athletes using tools like that, car buffers, & not reciprocating saw but something similar. The name of that one escapes me, but someone on the texans uses it. The problem is, you still need someone to massage you with it. Even legs, what you can reach, I find I can't completely relax if you're bending moving toward them, operating equipment.
(ot)My bizarre massage tool of choice is a silicon tile mallet. It's like a rubber mallet, but a little softer & doesn't stink. When I trade massages with amateurs, it's what I give them to use on me. It's rare for me to find a (not too expensive) professional masseuse whose techniques I prefer even to the hammer- you should see the look on their faces when I bring it up half jokingly afterwards, just to see how they'd react. I understand how much of an insult it is, & don't even mention it anymore. But I'm 0/4 with the hacks at massage envy for instance. Most others are not strong/dexterous enough to last, & degrade from muscle penetration into lazy rubbing 1/2 way through, or want to give you a "sports" massage that eats up a 1/4 of your time with stretching I can do myself, or just don't listen (I've had one spend twice as much time on the opposite leg I asked for extra focus on- that's my fault).
I found one once in a small town, brownwood, tx, that was amazing. I took her for granted until moving, assuming everyone would be as good.