Others will definitely chime in. There are many different ways to do it.
For me, I prefer to use a simple Mr. Clean Magic Eraser. It's a lot of elbow grease, but it works great and the chemicals on the awning will keep the black from reappearing for a long-long time, including over the winter months when in storage.
Simple to do, but hard work, working above you head all the time. Of course, this means moving a ladder around and lots of climbing up and down.
But: Make the Mr. Clean Magic Eraser wet, like a sponge, but not dripping. You want it filled with water.
Then simply WIPE, do not scrub, wipe a small section of the awning. Follow with a dry towel or a dry cloth. If black is still there, do it again over the black area. Again wipe, do not scrub and follow up with a dry cloth to remove the loose dirt.
Rinse the Mr. Clean Magic Eraser and do another small section the same way. Keep working your way across the awning.
When completely spray the entire awning with a garden hose. Let it dry. You won't see any black stuff for a long, long time.
When bugs get rolled up into the awning, simply touch those spots up with a wipe or two of the Mr. Clean Magic Eraser and follow again with a dry cloth. Your awning will always be clean.
Again, this takes work, but doing it once and not having to touch it again (except for squished bugs) for an entire year is well worth it.
The second time you do it, it will be even better.
Again, simply wipe the Mr. Clean. If you scrub with it, you can easily scrub a hole in your awning. So, always just a gentle wipe and let the chemicals do the work.
