Moved to feeders forum.
As was said make sure you are up to date on your tetanus shot (it must be updated every 10 years) and clean the bites thoroughly.. keep them clean to prevent infection.
There is no need to clean the rats before feeding.. snakes are made to digest everything in (or on) the rat.
I have 30 some snakes (not really sure how many exactly anymore LOL) and I feed all of them in their cages all the time. I do not recommend taking your snake out of it's familiar territory and tossing a live rat at it. Some BPs will just get freaked out by this, and may be at a higher risk of being bitten by their meal.