How to make your own non-toxic oven cleaner

I'm about to move into a house with an old, musty-looking oven. I peeked inside the other day, and realized that the interior could definitely use some TLC (there's a fair and unfortunate amount of baked-on grease stains going on in there). The appliance lacks a self-cleaning function, though the idea of firing up my oven to the point where it's that blazing hot scares me a little anyway. Courtesy of Martha Stewart, I just discovered the following non-toxic, no-risk-of-burning DIY solution I'm going to attempt over the weekend.

All you need is a little baking soda and water. Mix up the two to form a paste. Spread it all over the interior of the oven, avoiding bare metal and the heating coils. Let it hang out overnight, and then use a plastic spatula the following day to remove it. Easy, right? She also suggests lining the bottom of the oven with foil afterwards to catch future spills-something I'm definitely going to do going forward.

In the meantime, if you guys have any other genius remedies (ideally ones that don't involve super-harsh chemicals) for getting the gunk off oven walls, let me know!