[Delphinus]

I think butterflies are probably the surest bet for aiptasia control.

I'm sort of surprised that a CBB (Chelmon rostratus) didn't work because mine is an absolute bloodhound for aiptasia. I'll throw in a rock with an aiptasia on it and sometime he'll even have it eaten before I've left go of the rock and pulled my hand out of the water.

Other butterflies you could consider are the yellow/longnose (Forcipiger flavissimus) and the pyramid (Hemitauricthys polylepis). The longnose is considered "reasonably reef safe" but I can't find any info if it will pick at clams so proceed with caution. Supposedly it does adapt to prepared foods easily though and I've read it suggested somewhere to try one of these if you have a CBB that won't eat because the CBB will watch what the longnose eats and might try the same things.

The pyramid is generally regarded as the most reef-safe butterfly of all, so, should be safe to try, although I don't know if that also means it's the least likely to pick at aiptasia.