Sorry you're having a rough time.
You'll have to herd the cockerel into a corner somewhere and throw a blanket over him!
You have sheep, so do you have some Crovect?
My old cockerel had scaly leg mite. I put some Crovect in a jamjar, dipped his feet/legs in one at a time, once, and the problem was solved. It's the fastest, most effective solution I've tried. I suppose it isn't usually suggested cos not all poultry folk have access to sheep pour-on
If you don't already have Crovect, you might get some anyway as it's the best thing I've found against flystrike and other nasty itchy things, I treat my sheep every 4-6 weeks in the summer.