Re: Smelly hair....
It could also have to do with the shampoo you're using.
As well, make sure your pillowcase is changed regularly.
Washing it during the day will definitely help.....it will start to get "head odour" throughout the day...but at least it's not offensive to you.
My husband gets it (short hair and bald on top), but he does produce lots of oil. I kept changing his shampoos and found that Redken Clear Moisture doesn't encourage the odour or make it worse. Seems OK so far.
Just a few suggestions....but firstly, it could very well be your shampoo.
It's all a matter of perspective!