What has been helpful is getting inserts for regular closed shoes. Tony Grady who posts messages online here has a podiatric shoe store in Ontario and I just got a pair of Birk inserts from him. They were cheaper than if I purchased them locally and best of all, they are guaranteed for 60 days or your money back if pain is not relieved.
In a nutshell, for me the Birk sandals are helpful but for closed toe shoes, I prefer an insert to the Birk closed shoe.
Lisa