Aptasia

[tranvictor]

I have had a lot of success with just boiling hot water. Boil a kettle full, add some prime, and inject with a syringe. Even if you don't manage to actually inject the beasts the hot water still burns them to death. Then when you retract your syringe, pull back on the plunger part, and you'll suck the beasts into your syringe for easy removal. Just don't kill too many at once for obvious reasons.