I say, forget killing or even harming them.

I'd tell them to set up a tarp like a trampoline, get covered in paint, and sell the paint splattered tarp as a collaborative art piece.

Oh, wait, I'd have to pay them. Eh, lunch and movie passes worked for my nephew, so it could work on those two.

If all else fails, I'd convince them that Mr. Krabs has something for them.

I'm with the people that think that he still likes them, but just get irritated when they get out of control.

If he willingly did something with them, they might be willing to give him some space once in a while. And even then, he'd run into ol' Murphy's Law from time to time.