Are you talking about soaking the leg in Epsom salt? if your sure it's an infection you may need to use oral antibiotics too. please post a pic or explain better.
I use Epsom salt compresses on the leg until it is all healed up. And I agree that if the leg feels warm, then oral antibiotics are needed. A vet is always a good thing especially with infections. I understand if you cannot get to a vet, though.
I make the compress (warm water, Epsom salt, soak a rag in that and wrap the leg) three times a day if possible.