Flea-busters is not harmless to pets. It has an extra ingredient that can be toxic. The instructions on it tell you to vaccuum it up if there's any out where pets can get into it. I tried it years ago when I had a bad flea problem but didn't find that it worked any better than the diatomaceouus...
Another thing to try is nematodes - you can buy them on Amazon and I'm sure other places. You spray a solution of nematodes and water on the yard and that's that. The nematodes eat all sorts of bad bugs including fleas, don't bother the "good" insects like bees, and are completely safe for...