Shower Stud Wall Damp - Renovation

[novaf4]

I’ve recently discovered that my shower valve has had a leak over many years. It is located in a stud wall. We have cured the leak. I have removed tiles and pulled the rotten damp plasterboard out, which appears to be the normal type. The plan is to cover the void with aquapanel (or such like) and re-tile etc. My reason for posting is all about the wood battens. They have suffered quite a bit but not to the point where I need to completely replace them (which would involve tearing the whole stud wall down and starting over). So i want to dry them out and use something on them. What is the best way to dry them out? 1. Fresh air with window open? 2. Mini heater fan? 3. Dehumidifier? 4. Combo? 5. Something else?

Then what should I do? Wood hardener? Fungicide?

Thanks!