None of mine progressed to the wet version of the fowl pox, all stayed dry thankfully.
For treatment, I caught up all of my hens (buff Orpington and Easter eggers) and contained them as they were all free range at the time, just to make treatment easier on me. I had two waterers available, in one I placed oregano stalks, in the other a bit of apple cider vinegar with the Mother. I also rubbed them daily (and gently) on their sores with iodine to help them dry and flake off (hopefully) faster. Unfortunately a virus is a virus, and must run it's course. The Easter eggers were by far the luckiest ones, they had minimal affects from the virus. The worst of the EEs had one eye get foamy, and eventually scabbed fully over. But the buffs really suffered. Their large combs and wattles were covered in the scabs and one of them became completely but temporarily blinded by scabs over both eyes. I will not ever again buy a chicken with large combs and wattles because of this; the EEs have small pea combs and were able to be turned out about 4 or 5 days after I penned them up, mostly scab-free. The comb/wattle size may not be a factor because I never saw this mentioned in posts I read about fowl pox, but I can vouch for what happened with my chickens. The buffs however lasted 2 weeks, with the worst one taking almost 3 before I could turn her loose. During this time they did not act sickly, and continued to lay for the most part. I had never heard of fowl pox before in years of raising chickens, and really I seemed much more bothered by their condition than they did though.