I have had the same problem with my 'free exotic' WCBP, a roo, go figure. DO NOT put Vicks on their heads to try to prevent picking, it is actually quite toxic, chickens are very sensitive, and I almost killed my little Puff trying to save him. What has worked for me (one little Polish roo in a flock of 30 big pullets):
I washed his head in the sink with the sink sprayer and baby shampoo, applied some bacitracin (antibiotic ointment) and pulled all his crest feathers into a little topknot, using 2 tiny rubber bands (made for horse braids) to keep it in place. This covers the picked skin of his head well, allows him to see (wow!a whole world out there), and doesn't seem to attract the attention of the hens as much as the (albeit lovely) flowing white crest feathers do. And I think he looks incredibly cool and hip like this. I've had these stay in 3 weeks at a time - when it's coming out, I do it over. I've put some 'Rooster Booster' on there too, but not sure I needed it. My flock has lots of room to roam, but the picking problems seemed to happen quickly, and while in the coop. Good luck.