@^: You don't need to press F1. Just click on the dwarf/space him constantly and the new keg should replace the one you were holding (i.e., old keg goes boom).
Basically what everyone else said. If you have a sin, go use the Keg Farming technique...if not, I still recommend keg-farming style, but if you're gonna run an E/A you'll have to take out the couple of Mandragors before them during each SF cast up until Taameh.