I tried to jumpseat MUC-IAD last Oktober. I had no prior listing in either direction and had no problems. If it wasn't for a full boat, that would've been my ride home. I just paid my taxes and went to the gate. I ended up using a zed on LH (always have zeds for back up).

On a side note, I went to a UA ticket counter during some airport appreciation. It took them a minute to figure out, but they set me all up to get my taxes refunded in a few days.