The Sunbrella website says to use woolite and gentile cycle in washing machine - I've done this with pretty good success, if you top is large you might have to go to a laundromat that has the BIG machines...hung it out to dry - NO drier.
Yes it does and reading the maintenance and cleaning information on that site should be the first thing you do before trying to clean it.
Boaters and pooping birds have been at odds with each other since the first man hollowed out a log to cross the river. So far, the birds are winning.
If I used a pressure washer on my canvas every time a bird pooped on it, I would have blown holes in it by now. It's best if you clean up bird poop as quickly as possible because it can stain canvas and even gelcoat. The problem is, of course, more poop will show up within a few days.
I've never seen bird deterrents work. I've seen birds perched on the fake owls and I've seen them just hop over the fake snakes and spike strips. The "whirly things" only move when the wind is blowing and the birds learn to perch out of reach of their path.
I once saw a suggestion to put a dead bird on a pole on your boat. Apparently, it has to be a natural bird, not a chicken from the grocery store. I've never tried that but it seems impractical.
So anyway, I wash my canvas with soapy water and a brush when I see bird poop. It doesn't get it all off but it gets most of it. When it gets really bad, I remove it and wash it in a machine according to the Sunbrella instructions but that usually results in some failed stitching so I have to re-stitch that part.
The bottom line is, the birds have nothing better to do and there are way more of them than there is of you. They are going to win.