Annual blowdowns are recommended. I would highly recommend doing it on a Saturday morning. The valves at the bottom of the water heater tanks are usually not to the highest quality standards. If it fails or breaks, you have the whole day to figure out how to repair/replace it. I would also rcommend replacing it with a ball valve type of hose bib. These are full port valves so they tend to not clog up with debris. They also allow you to purge the water heater at a "higher velocity".

By using a valve that let's out more flow and pressure will actually have lower flow velocity going through the valve. Put a larger garden hose size on it and run it outside.

Higher velocity you can see when you put your thumb on the end of the hose to restrict your flow and pressure to crate high flow velocity. This will make the water shoot out and give a great distance at restricted flow rate and pressure. This is why you want your restrictions to be at the end of your run for better performance in your house.

Ditttohead is who I recommended for designing your water treatment system.