That is a very timely topic. Many people like to clean their feeders up at the end of the hot summer season in preperation for the “official” feeding season. First I make sure the feeders are empty, then soak them in plain water for about 30 mnutes. I then wash them in a liquid detergent (Dawn). I have a couple of different brushes I use and depending on the degree of “filth”, I may take the feeder completely apart for this. After thoroughly rinsing all the parts, I spray my feeders down with a 10% bleach solution to kill any bacteria that may have survived the cleaning.