Repurpose Old Tennis Balls by Client Services | Apr 17, 2018 | Learn | 0 comments So, you play a lot of tennis. What do yo DO with all of your old tennis balls? Some people use them as a dog toy. Here are some great uses for your old tennis balls. Submit a Comment Cancel reply Your email address will not be published. Required fields are marked *Comment Name * Email * Website Save my name, email, and website in this browser for the next time I comment.