While the tools Silhouette offers are specially designed tools to work with their products, you may have something around the house already that could work as well. When I saw the picture of their hook, I realized that we had something similar-a double ended tooth pick & scaler.  It doesn’t quite have the hook shape, but I was able to weed this lettering with it.

Try it yourself and if it doesn’t work out, you can always order theirs on their online store which is available 24/7. ^_^