I also had idea to submerge miner into oil, but in the end decided to avoid this. A/C will be enough for one device like in my case, and its not so safe to place tank full of hot oil in living room.
Anyway, you may find this advice useful:
Have anyone tried to completely submerge Avalon into mineral oil? That works very well for desktop computers.
Fluid would be too viscous for the fanz...

I've got a system that's submerged in mineral oil (quad E5-4650). Transformer oil to be specific (lower viscosity, higher flash temps, mostly synthetic, no PBAs). Fans don't really care, although that's not the primary circulation method (pump).