Ivermectin is more often used in stubborn cases or when the areas that are affected are quite extensive.
If your vet would agree to write a prescription for something like Goodwinol you should be able to order it online. It's cheaper that way, too. I think I'd be a little leery of trying ivermectin for a less severe case.
"We are--each of us--dying; it's how we live in the meantime that makes the difference."
"It's not what you gather, but what you scatter that tells what kind of life you have lived!"
"Be kinder than necessary, for everyone you meet is fighting some kind of battle."