Well... undoubtely butter or PB are far more efficient, as their fat content is greater... anyway... anything with fat in it can be used, if you take enough time to the THC dissolve in it.
I dont know how many hours it would take... try to search some recipe with milk and weed, to have some notion of how much time.
Anyway... remember to grind your weed as fine as possible, as it helps the THC absortion.
And for the amount, when i make weed edibles/drinkables, i put about 3x the amount i usually smoke... for me its enough...
So, good luck, and any questions just ask! :thumbsup: