I forget how this was ruled, but I suspect that because LDC does not have "target," "choose," or "to do X" in the text, I am able to trigger the effect. My rationale is that when I attempt to trigger the effect, LDC doesn't ever really look for a target, but rather just gives the ability (kind of like opening a window) for me to grab an attachment that meets the criteria (gold cost less than the Targ character I played).

The reason this is important is in cases where my opponent has out a River Blockade, I would like to be able to play a character and trigger the chambers, just to burn up the opponent's cancel before I then attempt to trigger another location's effect.

If I'm cheating, please let me know

If you can legally complete the initiation, you can trigger it - even if the effect cannot successfully resolve.

To legally complete initiation, you must meet the play restrictions (ie, have played a Targ character), pay the cost (none), and choose all specified targets (none - no word "choose"). If you can do that, you can initiate the effect - whether there are attachments in your discard pile or not. (This, BTW, is the exact same reasoning "To Be a Dragon" needed errata: you could legally complete initiation - thereby standing your best character - even if there were no characters in the dead pile to return.)

Normally, you'd only bother doing this if you wanted to play a cancel.

Thanks Ktom, this is what I thought, but I defer to you on all rules questions