Yamaha provides 3 choices — with a flush bag, muffs, or hose-port connector and suggests all three methods get the job done equally very well. Bag and Muffs: Engine needs to be vertical, run not more than 800-900 rpm in neutral for 15 minutes with the prop removed. Mercury's procedure https://www.linkedin.com/posts/anhometech_anhome-airpod-cleaner-kit-cleaning-tool-3-activity-7180579811667374080-EjnJ?utm_source=share&utm_medium=member_desktop