I've had the best luck with 7-dusting the pens and spraying the dogs with Lemon scented "Joy" dish soap and water. I take a spray bottle and fill it a 1/4 the way with the soap and the rest of the way with water. It's about as cheap as flea control gets and has worked fine for me so far.
Chris
I have used "dawn" before, muts smell a little better too.
