When using AQ salt for my boy BB's fin rot the salt stopped the progress of the fin rot but didn't improve the overall look of the fins,that only came later once he was back in his tank and 2 weeks on there's only the tiniest (and I mean tiny) spot of black left on his caudal fin.
His caudal fin and anal fin will never be perfect,the fin rot destroyed part of the fins and now the regrowth isn't smooth but a little bit wavy,like he's got curly hair
On the plus side his ventral fins have grown almost an inch since I got him a month ago and they're so long now they're longer than his anal fin,and so beautiful and delicate.
Maybe stop on Tuesday(that's a week) but you could go till Friday. I wouldn't suggest doing 14 days,which if I understand correctly is the limit.I was worried that the fins didn't look vastly improved so I decided to do 14 days,My boy had a funny/frightening episode on day 13 and i'll never go over 10 days now.If the spread of rot has been stopped,then really clean water and a good diet should do the rest, at least it did for my boy.