I use a heat lamp over my FT and he takes to it every time and every time I use a heat lamp..if u place the fully thawed mouse or rat appx 6" under it for llets say for about 5-10 mins depending on size ofcourse,there is nothing wrong with that and it won't cook the mouse,lol..that's a silly thing to think. Actually putting it in water depletes the nutrients I been told,so if that's the case put the FT in a zip lock then place in warm water. That's my opinion.
def feed in the enclosure,I been told that by many people and it's what I do. My one guy eats anything FT mouse or rat,live rat or mouse... My other is picky and will only eat live mice at the moment. Hoping he can switch over to FT and rats down the road.