what does leaving a peeled red onion in a room do?

Original question: May make room smell of onion.

Second question: No.

Probably empty the room!

Stinks up the room and attracts flies.

Makes it smell like an onion ...

It will dry out the onion and you will probably have to toss it out. 

Wrap it and put it in the refrigerator or dice it and put it in the freezer, use it when you are going to saute onion, would not work in a raw onion use as the onion will get pretty soft. 

It makes the room smell of onions. There are no health benefits whatsoever.

make the room smell like onion?

Hi,

Leaving a peeled red onion in a room is actually a catholic tradition that my family has been doing since I was on the boat. It will help create a catholic atmosphere and ward off the non believers. If you have found someone who finds it distasteful remove them from thy presence and pray immediately. down with Satan up with JESUS! god bless you.

It usually drinks all your beer, messes-up your remote and beds your girlfriend.  Geez how can you not know that!

Makes the room smell like onion. No health benefits.