He mentions glass beads... Wouldn't that be about the same as silica sand-blasting media? I thought it was pretty dangerous to be around when it's airborne, unless you have a respirator.
You don't want to be breathing it while sand blasting. Don't know about when it's not blasting. but either way, I can hardly stand the sand while at the beach, give me grass or concrete any day. So you won't see me swimming in a sand hot tub anytime soon.