Cooking them at least 1 minute will kills most germs. To make it completely germ free you boil water for at least 7 minutes (plus 1 minute per 300 meters above sea level).
Make it 10 minutes for risky water. The taste often is dirty. But why you thought there was something like tea? With some herbs or leaves added for the taste our ancestors centuries ago already overcame this problem.

waterkokenAn old medical writing in Sanskrit from the Indus Valley (Pakistan and West Indies from 2,000 BC, the Sus'ruta Samhita contains instructions: “Impure water must be purified by boiling on a fire or heat in the sun, or by dipping hot irons, or by filtering through sand and gravel, and then left to cool.”

Beer was millennia ago, more reliable and safer than water, because it was repeatedly heated and filtered.

A volcano boiler was used for over 100 years already by Western Irish fishermen. It consists of a metal bowl in which a fire is kindling. At the side it has an air supply opening. Connected thereto applies a tapered double-walled chimney. That is actually a double wall tank (with a pressure relief valve) where you can put in the water. Very little heat is lost. And by the very large contact surface of the boiler with the fire, and the strong chimney effect, water boils in a few minutes.
You can add sprigs and other fuel through the opening from above.
(They can be found in outdoor sporting shops with names as Kelly Kettle, Volcano - or Ghillie Kettle.)