Years ago, Monty Browning showed me how to sharpen heads on on a grinder with jewlers rouge. That head was so sharp, you couldn't touch it. When a professional sharpener comes to the hospital to sharpen my surgical instruments, he has an array of grinders, belt sanders and buffers. I bought a nice grinder, put a paper wheel like the one abowyer and Centaur archery sells. I turned the grinder facing backwards so the wheel turns away from you. For grizzlies, I use the fine grit to make a burr then go to he rouge side and remove it. I found this to be the easiest and extremely quick way for me. If I am traveling to wet conditions, I dip the heads in that plastic coating that is heated on the stove. I have heard some put chapstick, Vaseline, or beeswax to protect the edge. I sharpen heads for my hunting partners and shave the hair from my left hand and forearm till my hairy extremity is bald.
It use to be a real chore for me and I have all the sharpeners, Lansky, KME, files, ezy sharp,etc.