What is the easiest way to clean burr comb and propolis from queen excluders? As a novice (first year) beekeeper, I have split hives, combined hives, requeened, dealt with laying workers, worked with a swarm, was forced to take some surplus honey, and all the other general beekeeper things. However, cleaning these @#$%^&&**!! queen excluders has been my most daunting task. Help. Thanks.