What I have found to be the most successful is this:

I take the f/t items out of the freezer and I place them in ziploc bags to thaw out, I personally leave them out for 3-4 hours. Just depends on how long it takes until I can poke the side of the rat through the bag and not feel anything frozen.

Then I put under a heating lamp at about 85ish, maybe 90 if I had to guess and I leave it under there for about 45 mins. Then I'll go back and flip everything over to make sure that if anything was still cool on the rat it won't be after all. So once flipped I leave it alone for 45 mins again.

Then I go back in my snake room and I hit the old plate with the hair dryer to scent the whole room, and I blow it towards my snake rack. I do this for about 30 seconds which is sufficient enough. Then that brings all my good feeders to the front of the tubs and for me it puts them in feeding mode so a less chance of refusal. It's like when you walk past something cooking versus smelling the cooking first, at least for me there is a difference.

Well I'm sure everybody has their own way and my way takes a bit more time but I've had extremely good luck doing this for my balls. Now when I had boas I just thawed, heated under heat lamp then offered it. For my Rufous I just thaw then heat up and put in tubs then I reach in my tank and get them out and place them in their individual tub with the food and put the lids on and they eat on their own.