I wore my new cotton cashmere sweater for the first time tonight. I'm standing in line to buy some taquitos, and some guy says "hey, what's that on your shirt?" I reach behind to touch it, and I get this green and white mess on my hand. There is this huge streak of it on my back. Can it be easily removed? It's dry clean only. Anyone have experience getting bird crap out of clothing? Is the stain time-sensitive, or can I wait until Monday?