Is there any glitches for Cod 5's zombie mode?

As far as i know there are only 4 glitches. I know 3 of them which can be found here.

http://www.nextgenupdate.com/vb/call-duty-5-world-...

How to become invincible. Requires 2 people. This is very good.

http://www.nextgenupdate.com/vb/call-duty-5-world-...

And there's this one which is strange. It isn't a tutorial but it shows that theres someone on top of the couch on the stairs.

The 3rd glitch is simply getting an RPG and RPG jumping onto the couch and then your on the second story and the zombies wont be able to get you up there.

And the 4th glitch is apparently you can fly which no one really knows apart from a few people but i don't know where i can find a tutorial for it but i don't know if it's true or not.

I cant seem to find any but I did see this one kinda neat trick that is on youtube... Say you start out at level 1. Go behind you to the stairs. Get up where the crap is in the way (but dont buy the clearout) Turn around sprint and jump and make it to that tiny ledge thing. You will be above the zombies. Look on youtube for the video.. I cant find it again for the life of me...

But the ledge thing you jump on is very tiny It looks liek you cant get on it but you can.