My retic kills the rat fluff too and then leaves it be. Sometimes eats it, sometimes doesn't. I don't bother too much. If she doesn't eat for that week I'll try the week after that again. The retic will get going on itself if it has eaten F/T before anyway. Maybe it just wasn't hungry.
When I looked into getting a retic all the people said "they are garbage cans! They eat anything!" en fin.. I get one and she only eats rats and only sometimes too lol.. Well whatever. Snakes have really slow metabolism and will be fine for a long time after a meal.
What I'm saying is, if it didn't eat, take the prey out after 2/3 hours (personally I don't advise keeping those really young pups and pinkies in overnight just because they rot really fast) and offer again on the next scheduled date you were going to give it its meal. A week off feed doesn't kill your snake, neither does two or three, or double that.
Mine is eating weekly now, but still takes a really long time after striking and coiling. She leaves it be, makes a few rounds and climbs in her viv and then eats it after 30 minutes or something lol..