I'm one of the finger-nail polish guys, but I use it only around the primer more to identify specific groups of cartridges than as a water-proofing system.
Lubricants are fluids. By definition, they 'deform infinitely under shear'. As a practical matter, lube has the potential to move during storage into places where it shouldn't be. Using a lubricant to "seal" cartridges seems to be a potential misfire waiting to happen.
Shouldn't be an issue either way, but you only need one squib to have a life-changing accident.
I should add that in the early 1980's my father accidentally immersed a number of reloaded rounds in our lake. After being dried off, all functioned flawlessly.