I read this oneshot a while ago about Bobby and Sam going to either China or Japan to help some guy with this creature that haunted in tunnels (I think) and it was basically a character piece. Oh, they stopped at a lot of hotel-ish places and Sam was a bit uncomfortable using the public baths. The reason Dean wasn't there was because of his fear of flying and at the beginning I think Bobby recognized he'd rather have Dean with him. 

I really really liked the way the author captured the characters and am dying to read it again so if any of this rings a bell... thanks! (I hope I did everything right. O_O)