Another hint I have to offer, is, to make sure the mouse is heated enough. It is not something to do in a hurry; it can take a good hour or more to thaw a mouse thoroughly.
If the mouse is not warm enough, the BP will not pay attention to it (or be able to find it, really.) They sense their prey via heat. But then again, you do not want to actually cook the mouse. I just put the frozen critter into a bowl of hot water, change the water to be hotter a few times in an hour, and then feed it. I would try simply placing the mouse in the cage, and then placing a towel over the cage to avoid distracting your snake. He should just take it from there. Check on it every so often to see if he is at all interested.
Good luck!