I don't have a python, just use the traditional siphon and 5 gal. Bucket. I've been following the python, mold, bleach conversation. Just wanted to ask, are you sure the gunk stains in the pythons hose is mold, and not simply the common gunk and algae that accumulates inside filter intakes and canister hoses.
Even if some of the hose goo is mold; is mold exposure harmful to fish? I've never seen a colony of mold inside an aquarium before. Doesn't enough water flow outward through the stained hoses during the vacuuming to flush out any loose spores or debris?
I'm all for clean equipment, and if one wants spotless utility hoses; great, but are sterile siphons truly necessary?
Used tank water and a tube brush are all I ever use to clean my accessories. Just an educated guess, dirty, stained python hoses probably aren't harmful.