[lil louis]

Louis had another dose of Frontline a few weeks ago, and last night I found ANOTHER flea. I really don't know what else to do. I have bathed him in dawn dish soap, washed all of his bedding, and I am constantly vacuuming. I don't want to apply any chemicals to my carpets, so I have been researching online. I have found some people say Borax works. Anyone have any experience using this? Or does anyone have any other safe, natural suggestions to use on Louis and/or my carpet? Thanks!