I was gonna suggest something, but I think you touch on it. a way to conserve is to light your bowl without burning it. so when lighting with a flame don't let the flame touch the cannabis. what you are doing is vaping your bowl before burn hitting it. It has been prooven when we light our bowls the first light or hit usually burns off allot or most of the cannabis in the whole bowl. which is why allot of people have adopted the snapper bowl or snapper method when smoking. everyone gets a nice green hit and the snap is kinda cool. I still rock the old style of bowl where we load take a good 4 5 hits off of a gram or so then reload, but from time to time I snap it up, just gets messy and you have to clean your bong like 3times a day with snappers.