Yea I know there's the threat of them spreading. It seems like it would/could do that with superglue too could it not? Your'e still disturbing it and causing it to react unless there is some way to sneak superglue on them...
Even so, I'm more curious as to how in the world it got into the tank in the first place lol.
The superglue smothers it so nothing can be released. The idea is you cover it if its small or get it into its hole retracted and do it.