I should have been more specific in my post regarding wax application.
Regarding the primer, excess wax should be removed with a cotton swab. Using a rag leaves too much wax which will be deposited upon the bolt face after firing. Use the cotton swab in a perpendicular orientation to wipe the primer pocket perimiter. This will leave plenty of wax down in the crevice to achieve water tightness.
Regarding the case mouth/bullet seal, the excess wax should be wiped off with a tight rag held between thumb and forefinger while the other hand rotates the cartridge. This will remove nearly all the visible wax leaving only a miniscule seam similar in design to the grouting or caulking seal found around bathtubs and such.
The wax at the case mouth does indeed fire off when the cartrdge is discharged. I've found no evidence of wax collection in the chamber as a result of using rounds so addressed and I've been doing this on my 375 H&H ammunition for over thirty years now. (factory chamber and barrel)
I prefer not to use paint products on my ammo as they all have powerful solvents and the resultant vapour trails inherent in such products. The possibility of violation, while remote, has always nagged me. The wax works and has been completely free of contraindications in my experience.
I have never waterproofed my tactical ammunition as I am an avocational operator these days and seldom drag my gear out in unfavourable conditions.
When hunting elk and other big game with my old 375, I generally carry watertight ammo as I operate solo and without benefit of modern field quarters. How does one experience the primal drive of the hunt when encumbered with noisy machines and RVs with hallucinogenic colour schemes?