I'm a bit late on this thread but just found it now. Haven't kept sauritus but I do have a proximus. She started off only eating love feeder fish. I now have her taking fish pieces, unscented chicken heart and liver, and now even UNSCENTED mice! In my opinion, the biggest thing was gaining the snakes trust. She is more than willing to come out and crawl all over me. I think that being housed with my other big females helped her take to a wider variety of food. She was more willing to try when the others were feeding on these items.

Asist feeding is a useful tool, but I wouldn't reccomend it in this situation. Gain his trust and go from there. They aren't as crazy as people make them out to be.