After the wort is in the bucket I rinse the keggle well with a garden hose. Then a few swipes with a scrub pad to get the "gunk ring" around the top and scrub the bottom where the burner tends to leave a little burnt on stuff.
After that, another good rinse, then I store the keggle upside down to both drain and keep the debris and critters out. Another quick rinse before the next use and you're good to go.