The dog is the one that needs to see the "DOCTOR" for a diagnosis. You are the IDIOT who has decided to self-diagnoses it (despite NO MEDICAL DEGREE) and treats the skin with COOKING OIL (which does NOTHING) but make the skin GREASY.
You have NO IDEA whether the dog has: mange (and if so WHAT TYPE) ringworm, skin allergies, scabies, mites or WHAT. Over the counter worming medications do NOT (adequately) get rid of worms. NONE of them will treat TAPEWORMS, and all worms..... can be transmitted to HUMANS.
In the case of round worms, they ENCYST in the dog's tissues & only hatch out periodically in small batches meaning: the dog needs to be check BY THE VET over several two week or several months's time, to make sure the dog has none in its stool (that the vet can ONLY SEE in many cases, UNDER a MICROSCOPE).
Give the dog up to the local SPCA so it can get REAL vet care (you obviously can't or won't PAY FOR) & get put into a loving, INDOOR HOME. After you give the dog up, you can seek you own MENTAL evaluation, for the urge to "PLAY doctor" and do a horrible job of "vetting" a dog and therefore endangering your family with all sort of possible zoonotic diseases.