You did a good job at washing off the soap =)
If he isn't acting ill (lethargic, gasping for breath in and at surface of water, clamped fins, etc) then he should be fine. Just use hot water from now on and you'll be good.
I feel awful because I got a second guy this summer and have been doing the same thing. Last week he started eating less and now he is missing a couple scales on his head. He had this tiki hut deco that he completely crams himself in sometimes, so if it wasn't for the not eating I would have thought it was an injury from doing that. I started treating for velvet with Maracide because I thought the gold I see on him must be that, but now I'm thinking maybe it is just his coloring...(I have a photo on the velvet thread I posted). Could this all be soap problems, or would that have just straight out killed him?
Ok, so here are my options. Today was day 3 of a 5 day Maracide course. Should I complete it just to be safe? Or should I change all the water with nonsoap water and stop the Maracide? Or maybe do both?