>>16889137Or toxic, phazers, taunt, switcheroo/tricking a choice item, heal block, topsy turvy, any strong grass move, etc.
It's not broken, otherwise you'd see Smogon run it into the ground. The point is it's a low risk high reward strategy. Gastrodon is a great defensive Pokemon, Scald is good utility and even if you won't sweep, you usually take out at least the first Pokemon you trapped. And of course it requires virtually no team support, meaning you still have 5 other mons you can use any way you want.