No, blocking the exhaust doesn't flood the engine. It stops the exhaust from exiting, and if the engine cant get rid of the exhaust, it cant take in new fuel, no fuel means it stops running instantly, end of story. You obviously haven't tried it, or you would know it will start right back up again with a single tug on the starter....

I've done both (pinch fuel like and block exhaust). I like the blocking method better because its faster... Its also much easier when you have a body on.