Yes, it is usually my "starting point" also, Marshall.
I didn't click on the source for the statement about using Rubber Boas to help people overcome their fear of snakes. It looked a little weak just as a title. Besides, I think any snake is disinclined to bite if it is not frightened. Maybe a BIG boa would be interested in eating an adult human but . . .
It still wouldn't occur to me to suggest that people can have a blanket faith in how passive a snake is. The authorities might show us its mouth - like whether it has teeth, or not. I suspect it has teeth. I've seen them in the wild, even handled a tiny Rubber Boa. It didn't seem possible for it to have a large enuf mouth to inflict a real bite on me.
I'm not an expert snake handler. And, have no initial intention of handling any other snake I come across - nonpoisonous or not. You, however, want to have a relationship with a snake as a partner in pest control. I think it might work and it might work if you can come across a Rubber Boa. It really could be that you'd be standing there jumping around saying, "Sic 'em! Sic 'em, Clem!!" And, getting zero response from your boa. I wouldn't want to count on getting away with fanning him with a towel, rubbing his shoulders, straightening his trunks and slapping him on the butt as he moves back into the center of the ring, either! Maybe .
I bet it would work best to have 2 of the same species in there so they can give each other snaky encouragement. "Easy Money! "One, Two, One, Two!" "Hook him!" "Hook him!" "Get inside!!!"
Steve