Have they tried isolating the snake with the food, say in a paper bag or small container (with air holes), overnight?
The food should be the same size around as the largest part of the snake's body. Some snakes will eat things that are huge, but these seem to prefer tummy sized prey.
Mine prefers to eat female mice over male mice, but I've found that getting the f/t mice around 70 - 85 degrees and dangling or walking it along in front of him works regardless.
I recently visited a friend with a large bp that hasn't eaten in a month. She was offering food to him in the cage and the cage has two hides and a small water bowl, aspen bedding, vines, and hardly anyplace to move around. I suggested a larger enclosure, bigger bowl so he can soak, and to remove the hides and water at feeding time and put some newspaper over the aspen. Mine will move around a lot when he's eating and needs space to do the constricting and getting the mouse in his mouth. So he's got about the equivalent of 10 gallons of free space at feeding time to do his thing.
I hope it eats for them soon
