I actually managed to get that achievement the legit way.
But i understand you OP.
It's incredibly easy as long as you don't get hit as you are running in before the 1st add has even appeared... Normally someone runs ahead and if you are left behind you get splashed even if you are on the stone bits of the floor rather than the water. Not sure how anyone would find it hard enough to ever bother trying to cheat for it.