How to set StartMediaIds on a user?

How do I set StartMediaIds on a user when it can only contain integers, and all folders are GUIDs ?

It still has an int id underneath, Umbraco just removed (prematurely in my opinion) any easy way of seeing the ID in the backoffice.

This would not be a problem if everything had moved to be key based but they have not as you found.

The quickest way I have found to find it again is to search on the guid in Examine in the `__key` field.