My girlfriend has a dishwasher. She also has a wire mesh in her sink for filtering out particles. I personally prefer an actual stopper, as I like to fill up the sink with soapy water when I wash hand wash dishes.
Regardless, sometimes I like to load the dishwasher up with things that dont get washed every day. Things such as parts of the coffee maker, wire brushes, sponges, copper scrub pads. In other words, when I clean the kitchen I like to stick anything small enough in the dishwasher. Part of this includes the drain catch.
Unfortunately, I do not clean the kitchen in an orderly fashion. As a matter of fact, I usually start cleaning the kitchen while preparing lunch, and never arrange it so that the dish washer is started immediately after I finish my dessert course of a sour pickle and some kim chi.
As such I always forget to throw the catch in the dishwasher. I think I will have to buy the girlfriend a second drain catch so I can always have one in the dishwasher. It would be much easier to integrate a drain catch swap into my diswasher unloading routine than to decide that I'm going to cook lunch, eat it sitting down, and then clean the kitchen in an orderly fashion.