I've tried the vodka a couple of times. It worked well on two of the smaller pullets. I had one hen that was about 8 or 9 months old that had stopped laying and was having having respiratory problems. I tubed her with probably 30 ml of vodka. I figured it was enough to put her into a coma if DH didn't do the job correctly. She didn't get sleepy, and I had to leave so I left DH to do the job when she got sleepy. She never got sleepy. By the time I got home hours later she was still walking around like normal. I decided if she could survive 30 ml of good Russian vodka, I'd let her have a second chance. She lived a couple more weeks before her comb turned purple and she stopped eating. Then it was time to get out the hatchet.
I have to admit it has gotten easier to do the culling. It is never easy though since I raised all these little guys by hand, most of them in the house, and a lot of them even hang out on the couch and watch TV with us. Once they have a name it is hard to see them go.
ETA - looking back, I think the hens that weren't affected by the vodka had very slow crops. They weren't impacted, but they also didn't empty normally. I find this to be somewhat common in my Marek's birds. I have successfully treated the sloIw crop just to have them die a month or two later.
if there is a next time, alcohol, at least so they wouldn't fight.