Re: Differences between hoses (interesting find)
Yeah, i noticed wooden tips do have a "different" taste than plastic or Alum endtips. Remember, wood is porious and will asborb smells/taste/moisture.
But a good DIY hose or Nammor is a god-send; but as daedra said, they are HEAVY and somewhat stiff. Take care at first to not tip over the Hookah - you'll quickly learn how to handle them. They really are nice hoses, well worth either the time of construction or the price (as in the Nammor).
And as to WHY your MYA still rusted with no water ran inside - water vapor from the smoke. As well as when you blow thru the hose (base clearing and clean-out). It condenses inside the hose, so if there's a leak in the plastic lining (or no lining) the steel coil inside the hose will rust.
KM hoses are leather, so I beleive they lack the wire coil (or atleast aren't directly exposed), but will pick up the flavors of the smoke faster (and NEVER should have water anywhere near it).