Found a good sunroof drain cleaner - PeachParts Mercedes-Benz Forum
Rain leak fix/sunroof drain fix VW MKIV
Cleanout rear sunroof drains on Wagon
Total tube brush length is 60 , bristles 2 and bristles 2/5 in diameter. Made from food grade stainless steel and nylon bristles, the head is soft
Long Wire Brush sunroof Drain Cleaning Tool for car and Fridge 60-inch X 2/5 inch
Cleanout rear sunroof drains on Wagon
Sunroof Drain Location on 2006 Passat?
How to Clean Sunroof Drains w/ pictures!
Upgraded Auto Sunroof Drain Cleaning Tool, 78 Inch Flexible Drain Brush Long Pipe Cleaners for Car, Tube Cleaning Brush Slim Drain Dredging Tool Perfect for Car Sunroof, Windshield Wiper Drain Hole
Cleanout rear sunroof drains on Wagon