I put 3 gallons of hot water in a 5 gallon bucket with a little Clorox bleach, hook my Python up to a Mag 5 pump, place the pump in the bucket and the other end of the Python in the bucket as well. Turn on the Mag 5 and let it circulate the water for about 30 minutes. When the time is up my Python looks almost as good as new. Replace the dirty water with fresh clean hot water and repeat this process to remove all the bleach.
I only use my Python to remove water from my tanks and therefore no worry about the bleach getting into my tanks. I use a drinking water safe hose to fill my Brute container for water changes.
Hope this helps.