Yeah,that sounds like Brown jelly infection from your description.
The problem with dips is that you can further weaken a coral.They have protective slimes whitch they shed off to rid themselves of pathogens and other bacterial diseases .ect..
Dipping removes some of this slime -over dipping and it will kill it as it can remove to much making it vunerable to secondary or re- infection.
Its hard to say how long you should wait ,does it look any better ? If not try try the fresh water dip,put it back in tank out of bright light with gentle flow.
Good luck alex