The tape can work, but you have to make sure that you don't end up with it between the outside face of the BB shell and the BB, which will lead to creaking eventually. This is assuming your BB shell has actually ever been faced, which is unlikely of course. Grease is completely fine and more than adequate for steel frames. For Al frames that get ridden in the wet there is some justification for using teflon tape instead, but I never do. Again, chasing and facing the BB shell is worth a mile of tape and a pound of grease.