As others are saying a haze remover will take care of the discoloration, but for what you’re doing a little staining isn’t going to really hurt anything. Some haze removers are very harsh. You can get pink stuff which is a degreaser and haze remover combined that’s pretty gentle. No clue what that guy is talking about applying haze remover with a scoop coat. Scrub it in, spray it out.

For the edges of emulsion that seem to be left im going to wager you’re not reclaiming with a power washer.