I tried it once using a substitute BP (don't recall which one) and will not use it again. In a 50 caliber rifle shooting REALs I ended up with thick, gooey, asphalty sludge. I don't recall how many shots I fired (I'm starting to sound like Hillary with all the I don't recalls).
I just use cooking oil or crisco mixed with bee's wax for the REALs. I coat a few all the way to the top ridge to use as a first shot. The rest I just have enough lube to fill the bottom groove.