I normally use chain mail and warm water to clean my cast iron pan, then dry with a paper towel before stashing away in a cupboard. If the pans are well seasoned, is there any potential rusting issues with simply hanging them up to air dry?
The way you have worded it, the risk can never be reduced to absolute zero, so there is some potential risk. But the probability of rust happening is very, very low, so in practice, you can do this for ages and not experience any problems. Also, if you do, you can just strip and reseason.
Also there is an option you didn't mention: usually you still have a hot hob when you have just finished cooking, so you can wash immediately and place the slightly wet pan on the hot hob, where it will air dry in seconds. It doesn't work every time (e.g. if you served your food in the cast iron vessel in which it was prepared), but when it is available, it is best practice to make use of it.