How effective is tea tree oil on?

How can I add tea tree oil to the warm exhaust of a Dyson vacuum without gumming anything up?

• I saw that tea tree oil is being used inside winter-shrouded boats to keep down the mold and mildew; the oil is placed in front of an interior fan.  I tried this in my bathroom by taping a tea bag onto my fan and dropping a bit of oil on the tea bag.  Works great. Now I have bigger plans.  The Dyson (or any vacuum) has nice warm air blowing out; I just want the air to pass over the oil on it's way out.  So I was thinking I'd put a few drops of oil on a cotton ball and then stow the cotton ball ... somewhere. Putting it in the canister doesn't seem to work; I've already tried that.  I want to smell tea tree oil in the warm air exhaust. I'm also worried that using oil is a bad idea.  But how can there be a water-based tea-tree oil?

• Answer:

  Where the outlet is, you can clip car air fresheners. Of course, you'll have to mix your own tea tree oil. Go look up on reed diffusers to get an idea.