Good plan on the manual removal. Your tank is too small for any type of flatworm-eating wrasse imo. 6-lines usually get really aggressive, and smaller tanks tend to magnify that. Fwiw, you don't need to dip corals in anything other than tank water for flatworms - they blow off easily with a turkey baster.

Pumpkin (I think) flatworm update
 

This morning there were fewer than yesterday but on scrutinizing my corals I noticed the large hammer was mostly retracted and was horrified to see the exposed base flesh had the dreaded beige dots on it. 😱

Taking Myka's advice, I got the trusty baster and was able to remove a bunch of them. After I got whatever I could (it's in a hard-to-reach spot) I used the baster to fluff a bunch of water all around it and they started flying off in all directions! So there were lots of them. I also fluffed water at my bubble coral but nothing came off it, which is a relief. Might be a temporary relief, but I'll take it for now.

My plan now is to remove whatever I see on the glass every day and keep fluffing water around anything that looks even slightly in distress. I will also adjust my jeboa wave thing so the area around the hammer gets increased flow and see if that helps at all.

And I expect I will be dealing with more, when the eggs, if any, hatch.

The other thing I need to do is figure out whether parameters, nutrients, light, temp - any of these - are in a range that encourages growth and reproduction of these things. If there's something I can change that impacts only the flatworms, I'll do that.

Sigh. It's a journey...

If you knew you could catch it, Id totally ad a wrasse for temporary pest control.

I recently had a bout with flatworms. I picked up some stuff called Flatworm exit and some carbon and gave the tank two doses over a few weeks time. Worked great! Knock on wood, so far I have not seen anything come back. Amazing how many there are you can't see and where they came out of. Good luck!

Flatworms seem all gone now...
 

Well it took a while but it's been four days now since I have seen any of what looked like pumpkin flatworms on the glass. The bubble coral looks a bit better and the hammers are opening.

I'll keep watching and hope they don't return in any great numbers.

Thx all for the suggestions!