Ian , there are a few guys on here who use the injections and have more experience than me. I was offered the injections and pump at my first meeting with my ED guy. I declined the injections in favour of Muse. With muse you put a thin applicator down the eye of the penis, not as bad as it sounds. It was hit and miss so eventually I decided on trying the injections.
At the first appointment the urology technician explained how the mechanics of the syringe worked and explained how to prep it and where precisely to inject it. The actual needle is very thin. Then it was trousers and pants down and under her instructions I injected the penis. After getting dressed I then waited in the waiting room for about 20 minutes, I then returned to see the technician for an inspection, there was some swelling but not a great deal. I refer to her as a technician because she is more than a nurse but not a doctor, she also performs biopsies.
Back at home a few days later i tried again and got a really good swelling, which was put to good use. As i said before I do have to get my head around doing the injection, perhaps the more I do the injections the less it will bother me.
I use the caverrject dual chamber which have been readily available in the last couple of months.
Hope that helps, thanks Chris.