I'll give some of those suggestions a try.

The frozen thawed I'd offered were heated either in water or under a heat lamp prior to being offered to him. I am not new to transitioning snakes to take frozen thawed prey, but this guy has been my toughest holdout yet that I still hope to get switched over. He has no interested in any other prey besides what he is currently eating - domestic rats. I dare not offer a mouse again, for fear of him going back to wanting them by the bucketload!

I have tried birds (chicken & quail) in the past, both live & dead & even butchered, chicken and turkey broth dipped rodents, other rodent species (African Soft furs, Gerbils, Hamsters) with absolutely no results.

I'll give the soap a go next time I feed.