Remove local path without setting new local path

I configured by mistake a local path in my workspace for a project in tfs at the project level. But I wanted this mapping only for subfolders not for the project level.

So I edited my workspace and removed the mapping and now it is not mapped.
I cleared the cache in appdata folder, rebooted but although there is no mapping in my workspace, the project in source control still has the old local path as a property. (right-click, advanced, properties, "local name" or also the local path in the title bar of source control explorer).

Right-click, advanced, and then "remove mapping" is not available, because the mapping has been removed already. I can map to a local folder, but I don't want to do that, I want it to display "not mapped".

You need to:

1. Run the tf workspace /delete command to delete the specified workspace.
2. Clean the local cache on the client machine. Delete the cache folder under path: C:\Users\username\AppData\Local\Microsoft\Team Foundation\5.0 (assume you're using TFS2013)
3. Create a workspace with that local path to target to a sub-folder under team project.