I would have imagined that, given the power (or lack thereof) of the jets, and the nature of the way they work, combined with gravity, if a ragdoll corpse was constantly jetting, it would merely writhe around on the floor a lot. Maybe it would spring up a bit every second or two, but I very much doubt you'd be seeing bodies flying around everywhere. I could be wrong, but that's what I would have thought. Implementing this would probably be a lot harder than merely keeping the jets switched on.