A lot of us men walk around with some clenching going on, mostly unaware of what you're body is doing down there which causes the pelvic floor muscles to tense up and stay that way. This tension restricts blood flow and can be serious enough to restrict flow in your urinary tract.
So, to start there is some light external massage on the lower abdomen and lower groin areas. Then, ya, the glove comes on the lub comes out and anal penetration. Not exactly pleasurable, the therapist then applies a bit of pressure at various points just inside where the pelvic floor muscles are situated by rotating their finger. As this is happening they have you do these breathing exercises to put pressure on the muscle to help them relax. They will give you some physio exercises to do between visits.
This helped me out as suddenly the LG could get quite hard again. I still need some pill assistance now and then, but mostly for keeping things going for the longer sessions.
Hope this helps as this was my personal experience. Might not be the solution for everyone.