I've heard said:

"the solution to pollution is dilution"

which rhymes nicely, but the root relations don't hold up. (Nor is it a particularly sustainable way to deal with toxic waste.)

According to the appendix of my aged American Heritage dictionary, there are two different meanings to the Indo-European root leu-. One has to do with loosening (solution), the other with dirt (pollution). And dilute comes from lou-, having to do with washing.