Advice needed

My partner and I have this very sweet boy. His name is Moxy, and he had to have one of his back legs amputated. Right now he has fleas really bad, theyre mostly all huddling around the side of his neck he can't scratch. Its gotten so bad he's getting sores, and no matter how much we scratch for him, he still tries to go and scratch his neck with his lil nub. We're trying to keep on track with giving him baths, but we're in a rural village and don't have a car. We can't get flea shampoo, since we have no way to drive the 40 minute car ride to a store. What do we do? It breaks our heart seeing him like this, our poor boy has gone through enough. I hate fleas. How do we help him?