I just found something while playing Taxing 8 ("The Art Gallery") as part of the "minimum skills" thread. Remember how you can make miners fall through terrain without actually breaking it? Well, I've just found that bashers can too. It requires a very specific terrain formation, which this level provides, but on the plus side, you don't need a second skill (like the blocker used in the miner trick) - the lemming just falls.
The spot you have to bash from is beneath the left side of the rightmost ball - there's a light-blue colored pixel of terrain that the lemmings walk on. If you bash to the right from this spot, the lemming will take one swing, slide across and down, and then fall.