I’d treat it as a two-stage job: soften the mess first, then clean the surface gently. Put on disposable gloves, grab a couple of paper towels, a plastic scraper or old credit card, mild dish soap, lukewarm water, a soft brush or sponge, and a clean cloth. Avoid wire brushes, scouring pads, bleach, and high-pressure washers unless you know the finish can take them, because those are the quickest ways to dull paint, scratch metal, or strip wood.
Start by laying a damp paper towel over the bird poop for about 10 to 15 minutes. This softens the droppings so you can lift them instead of grinding them into the finish. Then pick up the solids with a paper towel and use the plastic scraper at a low angle to remove anything stuck. Don’t scrape hard, and don’t use a knife. Dispose of the waste and gloves safely, then wash your hands.
Next, mix a few drops of mild dish soap into a bucket of lukewarm water. Test a hidden spot first, especially on painted, powder-coated, varnished, or oiled furniture. Wipe the area with a soapy cloth or soft brush, working gently from the outside in. Rinse with a clean damp cloth so no soap residue is left behind, then dry the surface immediately with a towel. For metal, drying helps prevent water spots and rust; for wood, it keeps moisture from soaking into the grain.
For fabric cushions or sling chairs, check the care label first. Blot rather than scrub, use a mild soap solution, rinse thoroughly, and let everything dry completely in a shaded, airy spot. If the furniture is wood, avoid soaking it and consider re-oiling or resealing if the finish looks dry afterward. For wicker, use a soft brush and don’t let water sit in the crevices.
If there’s a lingering stain or sanitary concern, use a disinfectant that’s safe for the material, or a diluted white vinegar solution on surfaces that can tolerate it. Again, test first and rinse well. The main rule is simple: soften, lift, clean gently, rinse, and dry. That removes the mess without sacrificing the finish.