Cleaning your patio cover is a lot like going to the dentist; its not fun but it has to be done. Here are a few tip that might help and after its over, you will get to pick a small toy out the the surprise box!
The Underside
The ceiling does not need too much attention; perhaps just once a year, wipe it down with a kitchen spray cleaner with bleach to prevent mold and algae from forming. If you use a smoker or BBQ (grill for you Southerners) then the ceiling of your patio cover may become sooty and greasy. In this case, a de-greasing detergent might be necessary. Magnum Patio Covers Company uses high quality aluminum materials which are professionally powder coated and can handle most kitchen grade cleaners. If you have to step up to something stronger, acetone can be used however only sparingly and know that if you scrub too hard acetone can remove the paint.
On The Top
The top of your patio cover can be a challenge. Leaves and fir needles make a mess quickly so its best to use your blower and blow them off as often as you can. Then, two or three times a year you will want to use a car wash brush and car wash soap to keep it looking good. Add some bleach to it to fight the mold and moss. If you pressure wash, be sure not to hit the caulking that is over the screws. The gutters are narrow, so its best to hose everything down to each end and then scoop it out.