I would like to clean my air conditioner myself it smells awful. What would I use to do so. I could spray it with the hose outside would that be enough using just water, or do I need anything else to kill the smell.

Dear terry pring

An aircon does not smell. Even the collected dust on it does not smell.
Have you checked what actually the item is that is smelling?
May be a rat or mouse has died inside one of the units.
What you have to do is open the units and check properly what smells, and take it from there.
As to cleaning aircons : the best way is to use compressed air, to get rid of collected dust.
Success !