Well, lucky for me it is legal where I live.

I've read some more about it.
I think it may work a bit like this:
MJ can make you more relaxed -> less stress -> good for mg
MJ lessens cramps caused by mestinon -> you can take more mestinon
MJ lessens pain -> pain eats your energy -> you have more energy left
So.... Yeah, but thats just my simple thought

But I think the direct effect on our muscles is relaxation... And that's what worries me, I guess we're "relaxed" enough.
But I still think Im going to try it, Ill keep you informed