I found a recipe for homemade dishwasher detergent today which has already come in handy as I'm out of the stuff! You can either use this or mix it half & half with your store bought brand to stretch it. Every little bit helps!
Homemade dishwasher detergent
1C Baking Soda
1/2 C salt
Mix it all together. Use 1 TB detergent, and use Vinegar as your rinse aid.