I have pot socks and don't like them. They can someones fit loosely on the bottom of the pot and when you lift your pot out of the tray they fall off and its not fun putting them back on especially if you have a big plant in the pot. Plus I don't think they do anything. Landscape fabric works just as well. I just precut pieces of it up to fit the tray and put one in and it stays there even when lifting pots out.
Are you putting the sock on the outside of the pot?