I'd spray it with carb cleaner to completely degrease (I assume that was what "hypersonic cleaning" did?) and either run it dry or dry graphite lube it. I have yet to find any 'low temp' gun oil that works when it is -20F or colder. Degreased and dry graphite lubed has worked for me down to -40F without issue. I had a number of the dreaded 'clicks' in extreme weather before going to dry graphite.
Complicated actions with lots of moving parts like autos and lever guns need degreased too but I wouldn't run them dry and without graphite. Simple bolts from a bolt gun generally are fine dry though.
