Hi,
Is this understanding correct? I wonder if you have the wrong expression? 'To air' sounds like you hang something outside to freshen it up, to get rid of stale odours. I'd say people rarely do this.
Perhaps you are thinking about laundry? When people do the laundry, in the summer they sometimes hang the clothes outside to dry.
If my pants were smelly, I wouldn't hang them outside to air. I'd wash them and then dry them.
Best wishes, Clive