A Funny Bucket is a legendary maneuver, usually reserved for long road trips where no suitable place to relieve one's self can be accessed. The technique involves first expelling all gas from one's colon (creating a vacuum), and then urinating down one's chode into the vacuum of the anus until the expulsion of liquid is complete. The urine can then be retained in the colon for an extended period of time until a suitable repository can be reached. This maneuver takes skill and practice to be pulled off discreetly.
We were stuck in traffic in Canada, so I gave myself a Funny Bucket until we got the nearest KFC.