Was surfing a favorite website when I found this story.
Evidently, a man claims to have found a dead mouse in his can of Mountain Dew.
He sues Pepsi.
Pepsi uses as their defense that the Mountain Dew would dissolve the mouse carcass.
I don't know if this will make it to Mythbusters, so I'll enlist the help of blog followers:
Please, DO NOT use a live mouse. Get a F/T mouse from a vendor that sells them as reptile food (I am not endorsing that particular vendor, just giving an example).
Place it in a container of Mountain Dew.
For science' sake, put a lid on it, I would presume the carbonation would be helpful for any chemical reactions needed to dissolve the mouse. With the lid off, the soda will go flat, and it may lose some of its dissolving properties.
Also, keep it in an aluminum can. Plastic may or may not do. Better yet, try dissolving multiple FT mice in varying containers. Keep a picture record - at least one per day for several days.