I was doing it that way, and in fact, I still put a start date on the Waiting For task for when I subjectively think I need to hound the other person if I have not heard back.
I like them in the On Hold context until I actually have something to do. Meaning, I have a task to remind me to check my on hold Waiting For context, which I have grouped by Context (so I can see the specific child Waiting For contexts assoicated with people) and sorted by start date. So I just check which waiting for tasks needs my follow-up today, based on that sorting by start date. If I follow-up, and then I have an actual next action to do, I change the context to another that is active, give it the right start date, and log what I need to do (date/timestamped in the Notes field). TextExpander makes this actually very quick :)
I like the Oh Hold aspect as it indicate to me, that I actually can't do anything with this Waiting For list until I follow-up, and find out if I have a next action. And as long as I have my "tickler" task to remind me to check (every 2 days currently), I never forgot to follow-up, and know exactly what the history of the "back & forth" was by looking at the Notes field log I am keeping.
Hey, it works for me, Waiting For workflows seem to have a lot of different ways to approach it as I've scanned around on these forums and web. Again, what's so awesome about OF, customize it as you need. Waiting For tasks are always tricky, at least for me, because sometimes they go back-and-forth for a while, and it took me awhile to come up with a good workflow. The key for me is the On Hold aspect, and keeping the log with dates/times in the notes field.