Cake batter has a number of advantages as a WAM substance:
- It's readily available at supermarkets (which often have self-checkouts, avoiding strange looks from cashiers)
- It's not especially expensive in decent quantities (a $1.19 box at major superstore makes around a quart)
- It cleans up easily (water soluble)
- It tastes good, and you can select your favorite flavor (though the box instructions warn not to eat raw batter, that may be for the eggs, not the powder in the box)
- It's very easy to get different thicknesses (more below)
Good results can be obtained by ignoring the instructions on the packaging and just adding water and mixing. 14 to 16 ounces (415 to 475 mL) per box yields a quart of batter about as thick as if one was actually using it to bake with. Going below 10 ounces per box makes much thicker batter, but makes mixing it much harder and cleanup more time-consuming (because the batter is less diluted to begin with).
A note to new/virgin WAMers: cleaning any substance out of your ears is more difficult than one would imagine, and it's important unless you want to try to explain what's in your ear or why you smell like chocolate to others!