Hard to tell did it help and was it ich in my case but the treatment, as I described, did not harm my paros.
I did continued the full course until the dots disappeared.
With some experience now I agree with helen on subject of observation of behaviour is as important as physical signs.
On other side paros seem to be much more resilient than my chocolate gouramis.
I think any medication should be used as a last resort and very cautiously. Just because mine seemingly were fine is in no way an encouragement to follow.