yeah i thought about that too. but i think the main thing is to soak the filter in CLR for a good amt of time so it has time to eat up and breakdown the soap scum and build up to fully clean it out.
i just purchased the new mtm hydro 14.5001 and i love it... when it was foaming correctly. cant believe how fast these filters get clogged it and make the performance bad. guess it doesn't help when you have super hard water in the area.