Most of the guys here do not rinse the roof, in other words they don't use the over the counter scams or products that use scare tactics to get you to buy things.
If you want to rinse you can use the application pump you use to apply the chems, use a garden hose, use a pressure washer with large nozzle so it is soft like a garden hose, etc... Nobody here uses the water brooms or pitch witch.
Go read the roof cleaning section, dozens and dozens and dozens of pages of topics from past many years to read and learn about roof cleaning. Lots of politics and b.s. there too, don't get into that nonsense.
Reading those older posts will teach you about 80% to 90% of what you need to know, when you find things you don't understand or have questions about feel free to ask.