Al-Ko Stabiliser Hitch Gremlins

I have just returned from Diamond Jubilee Weekend trip and my hitch has developed a flat sounding squeek when turning - I have cleaned my towball with brake cleaner and dried it off using lint free cloth, as advised and shown how to do on the CC Towing Course.  The problem is not as bad but cannot find in my notes whether I can/should do the same thing to the inside of the Stabiliser Hitch.  Obviously they have to be perfectly dry to work and wonder if this should be my next step?  The caravan is just over 1 year old - I know some of you would advise taking it back as it is under warranty but we are off again very shortly and I do not have space to get it there - especially if it is only a few minutes job.

Any advice would be much appreciated, thank you.  Also, apologies if this has already been covered elsewhere, but do not have time to trawl through all the posts in this section and there does not seem to be a search facility at the moment.