Neil,
these seem to be quite popular,
what I have noticed when surveying is that an effect similar to bubbling is quite often prevalant, this can increase with a wet clean but I have found that is does dry back to its original status
I do stress to the custy the effect already showing and the appearance of the fabric before it is dry.
I mist with m/s aggitate with micro fibre cloth and hwe , bearing in mind not to use to high a temp, cold should suffice. towel dry and straight into the turbo driers.Cleaning does give good results
geoff.