HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\ShellNoRoam\MUICache
maybe that key is good to add by CCleaner guy to CCleaner?
i dont know
From what I can tell CCleaner already cleans the MUICache located at:
HKEY_CURRENT_USER\Software\Microsoft\Windows\ShellNoRoam\MUICache
I'm not sure if the location you listed is related or not to what is cleaned. I've only seen executible items added to the location I listed above.