I have the same issue with a type of centipede...thousands of them.

I have considered buying a cheap 3/8" rope and keeping it in a bucket filled with something quite objectionable like insecticide, oil, etc.

Then if you expect an "attack", lay the rope around the perimeter of the pool about 4-6" from the water.

I can't complete the task, however, because I can't come up with a fluid that doesn't have side effects (staining, cost, safety, etc)