If it avoids diffusing into air to the degree that you can scoop it up and pour it, I’d imagine that it’d pour out the same way.
But if you just want to get most of it out of your lungs — like, you’ve been breathing it and don’t want to asphyxiate — I imagine that exhaling all the air you can and inhaling air and doing that a few times would probably do a pretty good job, the way the Mythbusters video above did with the helium.
Sulfur hexafluoride does the opposite:
https://www.youtube.com/watch?v=FvvSIAqOkIw
IIRC it’s also one of the worst greenhouse gasses in existence, unfortunately.
Edit: the worst greenhouse gas. Why are cool things always secretly terrible?
Can you stand upside down to get dense gasses out of your lungs? Asking for a friend
I assume so. Here’s a video of someone floating a boat (apparently in air) in it, and then sinking it by pouring cups of sulfur hexafluoride over it:
https://www.youtube.com/watch?v=ee2NaYRnRGo
If it avoids diffusing into air to the degree that you can scoop it up and pour it, I’d imagine that it’d pour out the same way.
But if you just want to get most of it out of your lungs — like, you’ve been breathing it and don’t want to asphyxiate — I imagine that exhaling all the air you can and inhaling air and doing that a few times would probably do a pretty good job, the way the Mythbusters video above did with the helium.