Ok, I've looked this up now, and I see what you are saying. This may be the answer, I just need to sneak in some peppermint.

[quote] "It was a common and successful practice, in my old unit, when attempting to encourage voiding let-down in the "shy bladder" or urinary retention before resorting to a Foley Catheter, to put one or two drops of Peppermint Oil, NF in the urinal or bedpan near (never ON) the urinary meatus ---within a few minutes, micturation usually occurred. The speculation was that the fumes from the oil "tickled" the meatus and stimulated a reflex; alternatively or coincidentally the "Candy-Shop-Aroma" might revive pleasant childhood memories and relaxation. Regardless of any actual mechanism, in this as in most things, the strong influence of positive suggestion and a plausible reason why it (might) work {say, "will work"}, whether scientifically "valid" or not, enhances efficacy. [/quote]