Glad you area healing up well and that you have a new trap. Good luck, but I don't think there is every anything as 100% removal.
Edit: I'll be honest, I didn't even read this whole thread until now. The answer to the problems here isn't to keep adding creatures to the system if you are having issues, even if they 'eat' whatever the issue is. More eating/pooping creatures is not a solution. When we run into issues in this hobby, they last a long time when trying to address it. I've battles aiptasia in my tank for several years now. I finally got it all. Until I looked into the system yesterday when I got home from work, at least 6 new very tiny ones. Adding expensive nudibranch or filefish that I would have to care for with specific needs afterwards isn't fair on both the animal and the pocket book.
So, everything here is pretty easy to tackle if gone about in a logical way. Large water changes with ro
water on top of weekly water changes. Feed your clowns as they need fed, don't stop feeding because there are nutrient issues in the water column, stir up the sandbed during these water changes and suck out what you can.
These are all basic entry level issues that we all run into, and can easily burn us out. You can do it the right way or the wrong way, both are frustrating but only one ever shows results.