yellow bog brush

The yellow, liquid, jet that gentlemen use in lieu of the more standard toilet-brush.

As seen in Pride & Predjudice:

"Why mister Darcy, that really is quite a skidmark you've left in the pan, as offensive to the eye as it is to the nose!

Fear not Miss Bennet, for I have quaffed a goodly gallon of ale within this half-hour and am bursting. I shall liberally apply the yellow bog brush forthwith!"