I said take it home put it in the oven a 375 for about 30 minutes, that should fix her right up.
Not a good idea because if he actually did put them in the oven, and he seems dumb enough to do it, and all the toxic plastics get released it could be carcinogenic which makes you liable for telling him to do it since you already know he's as gullible as a kitten chasing a red laser dot right off the side of the sofa landing face first in the carpet.
Not only that, if it's a battery powered wireless mouse the batteries could rupture or even explode from the heat and the mouse could potentially catch fire and so on and so forth.
Yes, it's funny as hell but it's a BAD IDEA as I've known those silly enough to do such things and it always ends badly, especially if he decides the oven is too slow and uses the microwave instead! :)
TRUE STORY TOO: Worse case it'll melt all over the oven as I know this for a fact from personal experience when one of my daughters babysitters sat a battery recharger on top of the toaster oven, forgot about it, and then cooked something and the battery recharger melted on top of the toaster oven and yup, the batteries ruptured. Imagine the damage that would occur inside the oven. Ouch.
ANOTHER TRUE STORY: I once wrote a prank program for the director of engineering where I worked that globally hooked the mouse messages and randomly added a few extra pixels of movement and made the mouse skittish around buttons like OK or CANCEL and it was absolute hell to click those buttons. Put the prank program on his machine to make his mouse act wacky and waited. We heard him making comments, banging the mouse and the engineers finally lost it when we heard him take the mouse apart, clean it, blowing in it and really start banging on it. Funny as hell and the outright laughter finally clued him in that he'd been punk'd.