Can you use a damp meter on the wall and see if it is recording damp. Condensation comes from damp air. It may not be your wall that is damp. It may be coming from somewhere else
How do you know its wet ? are you using a damp meter or does it look wet. A damp meter will show wet with only 5% moisture so the DPC is doing its job and as long as the bricks are not painted they can breath and evaporate the moisture into the atmosphere