We've done the tough love thing with a few of our mouse eating ball pythons. Not until they have been with us a long while and not until they are quite a good size (not baby hatchlings). The first week we completely skipped the mousers (no food at all offered), then a rat pup each week after that. The longest time it took was 4 weeks of refusals but most switched after 2 or 3 weeks. All are now hitting those rats like they are going out of style!