Baking soda and apple cider vinegar (BS/ACV) is a "no touch" application. You pour your BS over your head and let it sit for a bit then rinse well. Follow this by the ACV in the same manner.
If you go for a dreadlock shampoo or Dr. Bronners then you would apply it to the scalp, massage it through the scalp with your fingertips, then rinse thoroughly. When you do this, the soapy runoff will handle the cleansing of the hair itself.
You should wash about 2-3 times/wk as needed and try to let it air dry. You can shake the excess water off in the shower.