Actually your boss was right, sort of...
Peroxide aids in reducing blod clots of the wound and therefore
should be used sparingly, especially on large wounds.
It should however be used to wash around the wound as it does
remove blood better than plain water, and alcohol burns your pup.
Ear wounds are very serious, especially penetration wounds, as the
ear has a significant number of blood vessels and bleeds easily. Simply
apply pressure to these wounds until the flow stops. Peroxide is
definately not an item you should use for ear wounds OR on cuts that
are more than 1/2 inch or deep.
I recently wrote an article on my blog that includes "dog emergency pack"
and some other dog emergency info.
My dogs are almost human and I treat them as such, I'm sure you do too.
By the way, this also goes for people, except we're only a little smarter
than dogs so we can pay more attention to our wounds.