My cats caught Sarcoptic mange from a stray I was fostering.

Does anyone know the exact dosage for giving Ivermectin injectible to cats, either orally or topically - and the best way to administer for mange mites? Do I need to add anything to the Ivermectin before giving it to them? I've heard Ivomec is a good brand, but do I need to get their 1% or .27%?

I've already tried Revolution and it just drove the mites the cat's extremities.

Thanks for your help.