The materials for this project are very simple and easy to find.
1. Plastic spray bottle - This can be any type of spray bottle. The one I used for this project was a little over four inches tall and one and a half inches wide. It has an attached cap which is very convenient, as it helps me from accidentally macing my friends or myself when whipping it out.
2. The spice - Many different things can be used for the spice. The simplest thing to do would be just to fill the bottle up with your favorite hot sauce. You can use store bought hot sauce, or make your own using one of these recipes
. If you are more interested in pure heat than flavor, you can make capsaicin extract as shown here
or buy the commercial version on eBay (make sure to use a public computer to create a dummy eBay account, and pay for your product with a prepaid credit card which can be bought at most convenience stores. As always, never use your real address for shipment, instead have it shipped to a PO Box which has no verifiable information traceable to you. These precautions will make it harder for Big Brother to track you). Water down the extract until you find the intensity that best matches your tastes.
Extra: It is a good idea to put some sort of identifying label on the bottle, so no one accidentally uses it as breath spray. For my warning I decided to use an image of a red chili. It is simple and straightforward, and the lack of words means that it can be understood by anyone from a non-English speaking country (Useful if you have to flee your home country to a nation with non-extradition policies)