the file that controls the Access, Stairs and Ladders application is called %pdmsui%/des/addins/access. Comment out all lines in that file and the menu entry will be greyed out making it impossible to start the application.
I thought that was the file you uncommented to get the ASL modeller (old method).
I'm after hiding the new sparkly Access, Stairs and Ladders that only really works properly in E3D to stop the never ending designer questions about why they can't use the new version.
My guess would be that there is a file in %pdmsui%/des/addins/ that if you comment out the command lines will either stop the Access, stairs & ladders option from appearing on the menu or grey the option out.