Something to represent a person, whether it be a photo, a drawing, or sigil, or a persons hair or nail clippings
a container that can be sealed tight
any other gas-causing foods
a few cups of water
Put the representative object and the other ingredients in a container
Wave your wand over the bowl while chanting and focusing all your energy and your hate for the person on the stuff in the target.
Cover the container so that no odor/gas may escape and store it in a dark place. Do not take the top off the container.
As time goes by the stuff inside will rot. As this happens, the target will start to get very bad gas, and the cover on the container will make it so the gas in the container, which is symbolic of the target's body, won't be able to be released or ecscape.