I would try a 5% concentration... Use either KB or Neogenic... I personally use KB, but it is hard to apply if you have longer hairs as it is sticky. A lot of forum users use Neogenic and I am going to use it from this Monday/Tuesday so cannot really vouch for it yet.
In terms of effectiveness, I cannot comment on that either as you can see my current regimen. God knows what causes regrowth and shedding on my head. All I can tell you is that I started seeing tiny brown/black terminal hairs around my hairline, some grow faster and some slower, depending on how long they were under influence of DHT.