I'm not an expert, but I think gleet can be reflective of other issues like crop problems and worms. I had a couple like that, and after trimming and cleaning bums, I wormed with Valbazen, and they are better.
It may be a case of favus or fungus in the comb. Try putting some Lotrimin, Tinactin, or some of the miconazole cream that you use on the gleet girl on the combs. Favus is contageous, so wear gloves when you put on the cream. Try giving your flock probiotics in their water twice a week to see...