Huh. With the TH messages in the log, we can actually test Millionaire's Desk now. I wonder if anyone has done that?
Well, during an interview/question round SE at one point confirmed that there are no items in the game that give the user an increased "hidden" Treasure Hunter effect unless it is explicitly stated so on the item itself. Then again, we all know what vague and lying bastards they are, so there's really nothing hurt by trying.
On that same note, i always wondered if there's anything that can lower droprates, for instance active quests or items in posession, since i feel i have the worst luck ever when it comes to this game. Always seem to take 10 times longer for something to drop for me. Personally went 1/150+ on TH6/7 blue proc brew'd Shinryu's before i even saw a body drop from there. Jokingly told everyone that the Mithra goddess of Luck and Droprates doesnt like me because i never bothered to get the mithra repelling rafflesia scent off me from the Opo-Opo Crown Quest, but maybe there actually is something to it. Well, not so much the rafflesia scent, but other active quests, items or unfinished progress in things?