About 6 months ago, I had the good fortune of finding a source for hydros in the Louisville area. While it's a bit too far for a regular trip down there (for me), after exchanging emails online, the owner invited me down and said I could participate in the hydro process. He's a tech/cave diver, so he understood why I wanted to minimize flash rusting inside my steel cylinders. All told, we did 8 LP Steel cylinder, complete with Plus rating, in maybe two hours... No.... not your typically turn around time, but we were also chatting quite a bit too.
It was nice to go through the hydro and "plus" process. So, even though it was a 4 hour round trip, I got a nice education, and my 8 steel cylinders back in the same day.