I've used a wrist-rocket (Slingshot) and a tennis-ball before with great success in small crawl spaces. Plus it's fun
Take a knife and cut a hole on two sides of the tennis ball, take your pull string and pull it through and tie it off.
Cheaper then fiberglass sticks and easier to work with in confined spaces. Works great for lacing cable through rafters.
Not to mention you can have some real fun with a dog
