I personally do the following:
Feed the majano (or aptasia) a bunch of food (so it's all fat and can't squeeze back into a hole)
Boil about 2 tbsp water in the microwave
Add kalkawasser until it becomes a thick paste
Turn off all pumps in the tank (it's best if you can remove the rock it's on to let the kalk paste dry on it, but this is second best)
Use a syringe...fill it up...and squirt it into & all over the majano
Cover the area surrounding the majano...cover it...cover everything that doesn't matter to you
Use a reef-safe epoxy to cover over the kalk paste over the majano
Covering the majano will make sure that nothing of it lives...otherwise you might end up with a tiny new one or a bunch of tiny new ones. Covering it with epoxy just is a 2nd protector against a new baby.