If the inside of your hose is dirty then so is your tank. I would suggest a good chemical treatment. As a first step I would add bleach to the tank and fill it up. I would ten run every tap until you get bleach smell, top up the tank again and let it all sit for a day or more. Then drain it all fill the tank up with fresh water , drain it through every tap, top up the tank again and let it sit another day. Lastly, drain the tank one more time, fill it up with fresh water and you are done.
This will get rid of any mildew or other living stuff. Dirt itself is not an issue unless you feel it is an issue.
I like having a charcoal filter in front of the galley
tap. It filters dirt and also any chlorine that remains in the water. I add a small amount of bleach to my water tanks
on a yearly basis to keep strange growth under control. The charcoal filter removes it before food