Striking a few matches and wafting them around so that they burn slowly and almost go out, thus creating smoke and acrid niffs, gets rid of any other aromas which may have theretofore predominated....
Lighting a candle in the lav or bathroom for a few minutes will also take smells out of the bathroom even if you are using an unscented candle.
A small cup or bowl containing vinegar also works. It can be kept "hidden" near the U bend.
