most of the time it takes less then a min for my snakes to take it but thats because there all accustom to it for your little guy it may take longer id give up after about 10 15 mins. you can refreeze them and thaw them again i dont refreeze them more then 2 times after that they get thrown away.
Also warming them up makes them smell more which the snake likes also makes it more realistically alive if its warm. and movement helps a lot too tail dangling or zombie dance my snakes are so used to zombie dance that that wont take a tail dangling rat.
you will have a lot better results with warmth and movement then a cold lifeless mouse just laying there =P and yes ur probably going to have to do this every single time you feed your snake but like i said all mine grab it within the first min because they know the drill. like i said tho i actually enjoy feeding time because i get to watch my babies all out attack a dancing rat =P
EDIT: he seems healthy and from what you have told us he seems to be acting perfectly normal "when hes hungry he will eat" XD just keep en eye out for noticeable weight loss thats when u should begin to worry otherwise just keep offering like every other day, eating strikes are very normal for BP's even with perfect husbandry