1. Use solar power via your Solar Scorcher from another project

2. Place directly in an open flame

3. Any other outdoor method of inducing heat. (Outdoors because potentially harmful gasses will be released and can smell up your house)

Place a layer of aluminum foil over the hole to prevent air from sucking back into the container.

Let cool for about 5 minutes

The goal is to heat the container up over 400C, and this can be done in a variety of ways. For example;When the container gets hot enough, the cotton releases gasses, including hydrogen and methane gases. As these gasses are cooked out, the fiber becomes carbonized through a process called "pyrolysis". This means that the fiber is charred, but not burned.You can tell the process is working because you'll see the gas venting through the hole in the top of the container. These gasses are flammable, and may ignite. Don't worry if they do because that's normal and just fine.The cooking is done when the gas stops and the flame goes out.Note: I've found that cooking them beyond the point where the gasses stop, and flame goes out, can negatively effect their performance, so take the container off the fire as soon as practical.Next;Note: The container is very hot, so use protection on your hands to avoid being burned while applying the foil.