WELCOME! to the forum.!
I don't have the same machine as you do, but I do have the heated hose on mine. I do get the contacts wet when I wash my hose but I make sure it is wrinsed well and dry before I re-connect it to my machine.
There is no way you can avoid getting the contacts on the hose wet if you are going to wash it well.
Hang in there for more suggestions and best of luck to you with your CPAP therapy and I'm glad to hear that you are noticing improvement.
I personally have only been using the vpap and climate line for around a month. However, when washing the climate line, I just washed over the contacts without issue. I make sure to get them good and dry before use. I haven't had an issue yet, but again, I've only been through a few washings so far.