[Itspuppyluv]

Orinskye is right. They are all toxic. You can find websites about dogs getting terribly sick or dying from Bio Spot, Advantage, Zodiac (which contains permethrin right? I've read terrible things about that). Even Frontline which I thought was a better choice. Some dogs do fine with these products, tragically some don't.
Flea collars emit a toxic cloud that your dog is constantly inhaling. When you hug them so are you. When you pet them the poison is on your hands. Flea collars are very dangerous to young children.
That doesn't help with your search for a good solution for controlling fleas but I couldn't read your post and not pass the info on.