PLEASE dont take him to this groomer. Amos has the same problems - his coat gets to a certain point and its game over. He has to be clipped twice a year. felting? Well Ive not heard that expression but I know exactly what you mean. He does NOT need to be sedated, nor will it take 4 hours. I was told the same when I took Amos for his first clip. I toured round to 3 groomers, desperately wanting to be told that they could comb this all through, but whereas they all told me the same story, which was that it all had to come off -

yes, I know - but the prices varied from £50- and four hours, to dont know, lets just see, to about 1 and half hours and £25 pounds. Needless to say, he goes to the hour and half and £25 option and he looks gorgeous. Admittedly, he comes out looking like a completely different dog - a bit poodly, but he looks wonderful and defo feels much better.
Sorry, but youve just got to do this, it grows back, and as I said earlier, only needs to happen twice ( if that) a year.