I would love to hear what the rest of you fine people have found the most effective bird poop remover from their Sunbrella canvas. Is removing the covers for professional cleaning a good option? Is there some kind of killer product that sprays on and removes the last of the white residue? The genius with the best product selection goes into my personal SBO Hall of Fame and, upon their passing, will attain "total consciousness". (a blessing from Karl, the greenskeeper. ) Thanks in advance for the help.