Has anyone used this flea shampoo?

has anyone every use Marshall Pet Ferret Flea & Tick Shampoo 8oz? I’m just wondering if it works. I figure it should be safe since Marshalls is the one that breeds all the ferrets for the pet stores in my area. my ferrets are on advantage but shes got one bugger flea that won’t die so i need to get some shampoo to smack it off. and are flea collars safe for ferrets? one site said to put a flea collar on them, but I’m not sure if its safe or where to get them.