A flush in the middle of the toilet-sitting process in order to reduce the aroma...usually performed on a "foreign throne" as a courtesy to the owner of said throne... in other words, to be polite and not stink up the host's crapper too much.
I gave a courtesy flush at the Smith's party because I didn't want to kill the next person to use the bathroom.
Flushing the toilet at the exact moment of a smelly bowel movement hitting the water as to minimize lingering oders that may eminate off the perpatrating poo. Keeping the bowl poo free will keep the bathroom odor to a minimum.
Courtesy Flush after releasing a smelly chocolate hostage
A term popular in jail. A courteous thing to do when you have a cellmate and are in the small confines of a jail cell. A method you perform when in the jail cell to eliminate the smell of your bowel movement. Usually executed at the point of release from the anus and before it hits the water. The suction of downforce of the flush eliminates the gases as well as the odor of the loaf.
"Yo, do a courtesy flush bro, that shit smells dude."