In the last year or so one of my fish had developed a strange skin condition that looked a bit like carp pox ... but also seemed to look a bit like Dermocystidium or Lympho... but not really definitely like any single one of them .... as seem in this previous thread: http://www.koiquest.co.uk/forum/viewtop ... 29&t=12734
Anyway in the end I decided just to leave it and see what happened .... the fishes head got worse, the look of the skin condition changed and it was still in a terrible state (although feeding and behaving perfectly happily) up to about a month ago when I found this photo of what is thought to be Epitheliocystis:

Some of the patches on my fish had developed to look a bit like this photo. The fish in the photo was completely cured using Acriflavine dips ... so I decided to give it a go.
Couldn't find a lot of info for Acriflavine doses for dips so I made a 10ppm solution and dipped the fish for two hours with lots of aeration ... then repeated this 5 days later for a total of two dips.
Now after almost two weeks after the last dip there is a definite noticeable improvement in the overall head area ... which was a great surprise and the first improvement in about two years ...

Not sure whether to treat with further dips while the water is still warmer (I'm unheated) or whether two dips will be enough?
The water temp will start to drop here soon ... and I don't want to miss an opportunity to help the fish if maybe more dips would be the best course of action.
Should I continue the dips with maybe even stronger doses (I found later that some people use 15ppm) or leave as is?
Opinions/advice welcome ... TIA