If the edges of hook and loop begins to fray, you could possibly use some Fray Check to prevent further fraying. I would recommend seam ripping the hook/loop and replacing it, however. Usually it's easier to fix it than trying to band-aid the problem. Here's a good visual on old hook and loop on some diapers. These diapers are OLD so you can see the loop has looked better. I sewed these probably back in 2012 so they've seen better days.