Hi Eve,
Thank you for your reply. Firstly, Mucky was not excessively matted. The only area that was matted was the collar area. I brushed him and took all of his mats out at home. It ,indeed, took me 3 hours to do so, but he was neither stressed, nor in pain. He is currently 100% clean and with no matted fur.
All in all, I very much appreciate the time you took to answer me and the fact that you recognised my dog's name. It's the only reason I am considering to return to Spaw in the future.