This method is a cost-effective swap that can save you money on dryer sheets over time. While browsing online for money-saving tips and tricks, I read about a cost-effective laundry hack that only required two items: reusable dryer balls and essential oil. What is the essential oil dryer hack, and what does it do? How to test the laundry hack at homeKate FrankeFor a standard load, I typically use two reusable dryer balls. Here's what Forté recommends you keep in mind about the essential oil dryer ball hack before instituting.