[USER=101916]@Chaos Brews[/USER]
Firstly many ways to skin a cat. But you want to cold crash. You should be concerned about suck back, drive without a seatbelt be scared.
I tend to dry hop cooler around 14 celsius for my IPA, but many warmer and some do it at colder temps. The hops are in anyway so that's a done deal, duration I'm DHopping for about 4 days. But of course you could drop the temp now for a few days and then cold crash at the end of dry hop duration and also pull the hops back up on your magnet.
However / But
As the beer cools the pressure will drop in the fermenter and pressure will want to equalise between fermenter and the rest of planet.
Your air lock is unlikely to have the vodka sucked into it during this process, after all when the beer was fermenting the vodka didn't get forced out! and suck back is just the process in reverse.
The issue that is essential is to keep oxygen away from the beer at all costs, so any suck through the airlock lets air in and the issues will commence, hence pressure capable fermenters with positive pressure useful as cold crashing they don't do that. That nugget doesn't help you though.
This thread does describe a method that will help
[URL unfurl="true"]https://www.homebrewtalk.com/threads/balloon-filled-w-co2-over-airlock-cold-crashing.689428/#post-9052929[/URL]
[URL unfurl="true"]https://www.homebrewtalk.com/threads/novel-suck-back-prevention.689946/[/URL]
You also mention transfer to another vessel to prime good swirl then bottle.
Again this just increases your oxygen beer exposure. I would just cold crash ( with suck back prevn) if you wanted you could inject some finings thru airlock hole removed and replaced briefly when beer cold and give a shake / swirl with the suckback mitigation in place.
Then when ready to bottle calculate your priming sugar, eg 3g per bottle ( use priming calculator ) then dissolve that in ( say you have 25 bottles ) 125ml of boiling water.
Use a syringe and put 5 ml per bottle, that way each bottle has correct dose and it's dissolved ready to go. Make sure you have a system say clean bottles on bench, prime with sugar put it on floor. That way you won't miss one or double fill one.
Drink your vodka ( not the stuff in the airlock) and just use some starsan or sod met solution in your airlock next time. You probably sanitise your airlock in starsan anyway not vodka i hope. During ferment the alcohol in vodka will get driven off by the co2 going thru the lock so in the end you probably have just water which you certainly wouldn't want to suck back into fermenter. After all if you leave the vodka bottle unscrewed there's less there after a few months.
