I think most of us here will agree that F/T (frozen/thawed) is the best way to go. It is kinder to the mouse and the snake won't get clawed or bitten when the fight between the two begins. And the nourishment is the same.
What I do is take the frozen mouse (I use the Munson Plan to figure out what size mouse my corn needs) and put it in a ziplock baggie. I thaw it in the fridge overnight (they do thaw quickly) and then when I am ready to feed I put the baggie under hot water for about 10 minutes until the mouse is warm (not hot) to the touch.
I personally feed inside the viv, I place the mouse on a plastic lid and put it in the viv. I will already have removed the snake and handle it for a while (I also use this time to weigh and inspect my snakes and record everything in a notebook), then put the lid in the viv and then put the snake in, trying to make sure the snake bumps its head on the mouse. They will start tasting the air and when they are ready they will strike the mouse.
There is a recent thread about feeding in the viv or in a separate container, I think it comes down to preference and convenience.
Good luck, and let us know how it goes!