I don't see why not. The odd numbers keep everyone in a big pile, so that's good. There'll be a lot of random soft bits squishing against you, so checkmark on that. And the smells will be so intermingled you won't be able to blame just one person.
I do feel inclined to address the concept of a 5some, and say that I think after four, you've got an orgy on your hands. (And if my experience means anything, that won't be the only thing you'll have on your hands by the time the night is through.)
You see, four is just two pairs of people, but five is a group of people. And that is an orgy, whether there's whipped cream, fisting, fluid shots or tugnubbing, the numbers make it so.
Go for it. Just make sure everyone's relatively clean beforehand. I suggest you get all five participants to take that stuff that makes you poop a lot before an invasive test. It's like an enema, but way deeper. A douche for all your inside parts. Then you can feel fresh and sleek to start mounting each other with every eager orifice.
Short Answer: Enjoy!