I just bought a new 617 and it is now my favorite one to shoot. I treat it just like my other S&W revolvers. I remove the cylinder and separate it from the cylinder crane/yoke. I place the cylinder muzzle end up. Then with a small stainless steel brush and some solvent, I scrub the muzzle end clean. It removes all the carbon build up and staining. Been cleaning my stainless revolvers this way for years. Never had any problems with any of it. I use q-tips to get down into the inside of the crane/yoke and scrub the breech side with the same stainless steel brush, and a bore snake through the chambers a few times. Put a drop of gun oil on it before reassembling. I plan to keep cleaning my 617 this way each time.
Just be careful and set your screw, yoke and cylinder onto something that will hold them, or keep them from rolling and falling, like a clean shop rag. And take your time.
Good luck