That’s instructions for ccleaner 6 (and an old one at that)
Network passwords (in 7.7) are found when you use custom clean. They are on the junk tab under the heading Windows. That said I just ran network passwords and it did not have a effect on my default.rdp (though I’m using the same user on the host machine as with the client so that might be why)
I looked through the rules ccleaner uses (ccleaner.ini in your ccleaner program folder) and no rules explicitly remove rdp files