I believe drying marks can be caused by water slowly running down the full length of the film and drying before reaching the bottom. One way round this is to hang the film to dry at an angle of about 45 degrees. Draining water then only has a very short distance to travel to reach the bottom edge of the film. It collects here and drains harmlessly away.
The problem is how to hang the film at an angle. A "dry run" with an old unwanted film is the best approach here. Trying to solve the problem with a wet, just developed film is not recommended.