My husky got sprayed once on a late night walk. She was so confused – she just wanted to be friends!
She got two jets: one in the facial area and another on her rump. The stuff near her face came out relatively quickly (think a timeline of months), whereas the spray on her butt really got the chance to soak in to her double coat. It would still smell ~5 years later if she got wet, just absurd staying power.
It did eventually fade or, at the very least, became less distinguishable from the general smell of wet dog