I did (and still do) feed my snake in a large-ish tupperware container (maybe 3 gallons) with no lid. I just placed the mouse in the corner nearest to his face and he'd always go right for it.
When I fed 2 pinks per feeding, I offered the 2nd pink when the first was about 3/4 down. As soon as he'd finish with the first, he'd go straight for the second. As soon as that second one hit his belly, I'd put him back in the viv.
Meg: The visual of a cornsnake getting confused as to which meal to eat gave me a giggle.