To make your clothes smell great and kill any germs add essential oils to your wash.
Any oil(s) of your choice - e.g. Lavender, Lemon, Lemongrass, Pine, etc... Avoid the heavy resinous oils e.g. rose, sandalwood, jasmine, patchouli, etc… as these may stain clothes.
Add 5-7 drops of the oil(s) to the softener compartment of your washing machine.
Dust Mite Wash
To help eliminate dust mites from bedding (as disgusting as it sound dust mites often live in your bedding feeding off the dead skin cells you shed. A normal wash will not necessarily get rid of these tough little critters).
Add 10 drops of Eucalyptus to the softener compartment of your washing machine.