Originally Posted by LuciferianSoul

If drinking this or that make things harder for you, don't drink it. Just do whatever works, but remember if you are relying soley on some type of food or drink besides water to perform, you're just using it as a cruch for your crappyness. So learn to sing well without having to 'drink thick yoghurt' or 'take a swig of vodka and eat some grass' or whatever the hell else people have suggested.

And practise.

If you lose your growling/screaming/whatever, stop for the day and wait until tomorrow to continue. Thats the point where you need to leave your throat to heal up.