This method works best with quick-drying materials that can be hung on a hanger.
The cousin to "the pull-up bar" is "the shower curtain rod" method for drying.
Just know that if you choose to use doorknobs to dry your socks, just make sure you aren't using the front door, as the neighbors might get the wrong impression.
This method is the "outdoor hanger on a nail." It is best used with thick materials that will dry slowly, and also best used if the outdoors are dry and warm. If the outdoors are not dry and warm, you may expect an abnormal smell to come from the clothes after a few days of "drying" without really drying.
The "outdoor doorknob" is a variant of "the doorknob" ideally the method that is used with a thicker material that must be outdoors to dry quickly.
This method is the "I've run out of places to hang very slowly drying heavy clothes" place.
Rotation is a key factor to air drying clothes with this method.