Has anyone used Sulfur granules to treat yards for external parasites (fleas, ticks, etc)?

I haven't dealt with the dreaded flea in many years and now after an isolated case it is proving difficult to manage them. I've got them on about 8 dogs now. I picked up salt, but I'm going to use it sparingly as I'm told I could kill trees with it.

Any one on the Sulfur?

S_B