I just don't feed my ball pythons in their living enclosure, period. I.e living enclosure has loose substrate.
I read on Yahoo answers someone said not to do this? I guess their reason is they confuse you for food when you do this. I don't get that statement. If that's the case then they would every time you take them out to handle regardless. If they strike you when you take them out to feed, then you've probably either A.) waited to long and they're hungry or B.) Have handled the mouse before relocating your BP. BPs have excellent taste/smell. For me it only makes sense to take advantage of that. Especially for a picky eater. Which implies, find what works and stick with it. Choose a second enclosure exclusively for feeding. It keeps the smell of dead mouse there, and not in their enclosure. Drop them in the box, they smell the food, and know it's feeding time. Almost like a switch. Just remember, begin de-frostingm when it's about time move the snake, then take the mouse out of the packaging. Don't handle the mouse first. Like I said they will smell it and think your hand is a tasty mouse.
I have had excellent luck this way, and have only been bitten by my oldest snake 3 times in 5 years, and my two youngest never bitten yet.