I suspect the most common failure of the processes is the surface tension of the liquid(s) being high enough to prevent infiltration through the flash hole.
I tested water submersion of ammo several times between 2008 and 2012. Some factory, some reloads. 9mm and .380 Auto, primarily. Sealed and unsealed.
Leaving factory ammo in a puddle (~1/2") of water overnight had no impact on performance.
Doing the same with handloads assembled with virgin components had a low rate of failure.
Reloads had a very high failure rate, with as little as 1 hour of submersion. (I suspect carbon fouling residue and micro scratches to be the cause.)
Reloads sealed with Markron were fine.
All 'failures' were damp or wet powder. The primers all still went off with seemingly normal authority.
But the real revelation came from proper submersion. In 4" of water, the failure rate increased substantially for all unsealed ammo. Powder was wet within 1 hour, in some cartridges. Some primers failed.
At various times, I would drop primed cases into the water. Results were roughly the same as with unsealed ammo. Some were fine after weeks under water.
In 8" of water, sealed factory ammo was dry and performed as new after 5
months of submersion. Markron-sealed reloads held out for as long as two months. Everything else had soaking wet powder within 9 hours and nearly all primers were dead after a week under water.
The primers had to be physically wet to fail to fire, which seemed to require at least a little bit of water column (and head pressure) to force the fluid through the flash hole.
Forgetting about one of the experiments and leaving the ammo in 4-5" of water for over 17 months resulted in a 100% wet primer rate. Whodathunkit?