Stuart sent this to me and asked me to post it for you. Be sure to look at the photos, which do a great job of showing the drop of saline he mentions.
"When we started using wet cannulation in June, we noticed that if a drop of normal saline was applied to the Buttonhole tunnel, it made the needle slide in very easily. Patients agreed. (See photos). Try it yourself and post your comments!
I asked him where the saline comes from, and it's withdrawn from a sterile saline bag with (obviously) a sterile needle.