Your dishwasher can multitask more than you might think. Here are things you can wash besides dishes:
Plastic hairbrushes and combs (clean out the hair)
Flip flops (if they're plastic or canvas)
Baseball hats
Dustpans
Potatoes (don't use soap)
Garden tools
Pet toys
Light switch face-plates
Mop heads
Makeup brushes
Fan grate covers
Hubcaps