I was taught to mix pickling lime with RO water to create my own anemone killing sludge. You just get an oral syringe and force feed them the paste ... it makes them melt like slugs and raises your PH at the same time !
The trick is, to get the right consistency. You want it to be like toothpaste when you're done mixing the water and pickling lime.
I had a huge aptasia problem in my tank, and until my lionfishes and my eel grew up I was happy to put my arm in the tank all the time to spot kill. I got most of them but they have recently come back. They're so good at reproducing, it's hard to really exterminate them.
" If a coral tank is a garden, then aptasia are the weeds. "