a couple weeks ago i cut my 2 males, they were about 1.5-2 feet tall. instead of throwing them away as usual, i said... "fuck it, im gonna try to make some butter out of them" honestly i didnt expect to get high at all.
so i used one cube of butter for both the plants. (I am assuming you know the process). i made one batch of 12 cookies. my wife and i each ate 3 cookies. and it actually worked. i was actually high, not some "i think im high", but legitly high. then next night we ate the other 3 each and same thing, no fluke.
so just make some potent butter and eat alot of the cookies and from my one time experience it should work.
also, i only smoke one bowl a night typically, so not a heavy smoker. take this into consideration also.