I actually have been doing civic parlays with some of the other NPC's in Khal, those that only required Domestic presence (which I had). Unfortunately, these won't give you the appropriate quest items (been trying from Diplomacy level 40 all the way to 75).
I'll definitely take the time to join the channel in-game, but I've tried the exchange broker already to no avail.
Originally Posted by Absalon
You don't need to complete the civic tutorial in order to do civic, but if you want to, you can do civic parleys with other NPC types. The quest suggests Crafters and Soldiers, but I think you can get Hearsay for Blackmail from any NPC type. It may just be that you are more likely to get it from Crafters and Soldiers.
Another option would be to join the diplomacy channel ingame (/join dip) and see if anyone has an extra piece of clothing that has 5 crafter and/or soldier presence. Or check on the exchange broker to see if anyone is selling any.