It appears that this remained in my inventory even after turning in the quest it was provided for. I didn't see any further use for it so I destroyed it.
I wondered same thing, went to Rizzle and it wasn't available as a quest..
You could always put item on AH for those too lazy to go do it themselves or even Guild Bank it to help out guildees as an alternative to destroying it.
Lol, I was going through my bags on my main today, cause I noticed that few quest items from Dread Wastes dailies did not disappear after returning the quests, and I found this. Couldn't remember wtf is this and what quest is it for, so I looked it up here, and from the comments I can tell that I've been probably carrying this around in my bag since forever without ever noticing it :P I think I'm gonna keep it :)