I have been seeing this at more and more dump stations lately, at RV parks, City Sewer Works, State Parks, Rest Areas, etc.
Has this ever happened to you?:
You have been camped at a site where there are no sewer hook-ups. You are all packed up and ready to head to the next destination, and you ease in to the dump station. You get out to do the dirty deed, and you find that there is an old rubber hose with no male hose fitting on the end of it to connect to the black tank flush in the convenience center. You say to yourself, "Self, I'll just hook up my grey water hose to the other end.". You look at the other end of their crummy hose, and it has a NPT fitting swaged on to the hose and screwed into another NPT fitting, and you mutter a few choice words that you would like say to their maintenance man. Sometimes you do find that the other end of their hose has a regular garden hose fitting so that you can hook up your grey water hose to, but not often in my experience.
This is how I solved that little problem!
I got two of the barbed fittings, one for regular sized hose and one with a smaller barbed end because I was at a dump station where they had a smaller ID hose that the regular one would not fit into. (Fool me once, shame on you. Fool me twice, shame on me!)
I suppose, just to have all of your bases covered, that you might also get various sizes of NPT fittings with a male garden hose end on it as well, but I would rather not remove their hose if is plumbed that way if I can help it. (unless it has holes in it and sprays all over the place, ....been to a couple of those dump stations too!)
Anyway, that's my story, and I'm stickin' to it!