Despite the instruction booklet on cleaning the filter cup, neither my husband nor I, have ever been able to get the filter cup completely clean. We've tried scrubbing with various brushes (even a tooth brush) & even sitting it in a hot bath of denture tablets. All to no avail. Eventually it caused our Dishwasher to flood our wooden floor, due to being unclean. It also gave me the "willies" to have that "never clean" filter sitting IN my dishwasher.
When I saw that they were now making a slightly different replacement part (different number but 100% compatible) I decided to get a new one. I have slight hopes that it will be easier to clean, when the time comes. If not, at least there will be a brief period when my dishes' rinse water, really will be clean, since the filter cup will be new. It was very easy to simply twist the old one out & then simply twist the new one back in place. (If this one does not clean any better, it will be the only time, I EVER buy a dishwasher with a filter cup LIKE this.) The dishwasher was labled as Kenmore Elite, but the serial numbers indicate it was made by Whirlpool.