Delete Unversioned Items of Externals in SVN

I have a project SDK in SVN that has externals to multiple projects. Eg. a project structure like the following in SVN:

Project_SDK __ Project1
            \_ Project2
            \_ Project2
            etc..

I am aware of the shift->Right click which brings up the 开发者_如何学运维context menu that allows me to delete unversioned files. However, if you do this at the Project_SDK level it does not delete the unversioned items in all the sub-folders (Project1, Project2, etc..).

Is there a way to delete the unversioned items from the Project_SDK level for all projects? Or is the only way to manually right click on each of the projects?

If not, what is the svn command to delete unversioned items so that I could create a .bat file that will automate this for me?

If you have a unix-like shell (cygwin or equivalent) you can just do:

svn status|grep '^\?'|cut -c9-|xargs rm

Maybe someone familiar with MS-DOS can help translating this to .bat?