I'd also say even if it isn't a case of being handled, the regurge could be stress related. How big is the tank, how is the heating set up, how big is the corn, is it all glass? wood? are there any hides? are there any small branches to climb on? What substrate are you using? Was everything in the tank cleaned before putting then in there?
Do you have them near anything that vibrates? I've seen a youtube video about something like this, and it turned out they'd changed their washing machine or something, and the vibration was driving the snake nutso.
Oh i'm not saying that they shouldn't do that also, far from it. All i'm suggesting is alternate reasons for the regurges, or reasons which could contribute towards them.
The snake is bound to be stressed enough from the regurge, and part of the treatment for it is to reduce stress by limiting / eliminating handling. If there are other elements in there which could be contributing to the stress then it would be a good idea to eliminate those also.
The only thing i handle him for is to hold him over his water bowl because i highly doubt he even knows where it is, and worry about him dehydrating.