I've been keeping snakes since the early nineties. Mostly boas, a couple of rainbows and a few dumerils. Just in the last year or so have I started a small collection of balls. I think I've been very lucky, because in all that time I just had one baby guayana that I had to assist feed. I have six balls ranging from a year and a half, to a couple of months. All but one switched to frozen thawed no problem. But one little guy only wants fresh killed. What I'm thinking is the ones I get from big cheese rodent factory, don't smell enough. They come really clean. So I've been keeping the live ones I buy on shavings for a bit, and hoping to use them to scent the frozen. And hopefully that will assist in making the switch. He's little so I don't want him to skip feeding. I know that probably wasn't much help. But I can relate to your situation. Good luck.