In 25man... well, after 50% we just let people suicide it then rezzed 'em, or maybe not even bother to rez. It's not like the dps is needed in the last phase! Can't do that in 10man of course, but for 25 it's silly how trivial the fight is.
These gimmick mechanics are rarely worth implementing into your strategy. You really should just play better and do it "right".
It's fun to think about and maybe even try crazy things, but the benefit is easily outweighed by the risk.