The better term is doll or poppet. You can use them for things such as Cursing, healing, etc. It depends on what you make the doll for, what herbs you put into it, what kind or color of fabric you use.
If you linked the doll to your friend, I'm assuming that you would want to use it for beneficial reasons (healing for example)? Anyways, so once you link the soul of your friend to the doll through baptism, anything that happens to the doll will happen to the person. However, this does not mean that if you set the doll on fire, they will suddenly catch on fire, or if you put the doll underwater, they will drown. Some examples of what I mean are like sewing the lips shut "Shut your mouth". There are many interesting and unique ways to use them. You could research and see different ways to use them.