Frequent Tuber Trophy in Tales of Monkey Island: Chapter 3 - Lair of the Leviathan

When in the brotherhood area there will be odd looking bumps in the ground. After going to the second floor (the same one Bug Eye is on) you can turn left past all the gold/treasure to find 3 in a group. 2 of them you can use back and forth, and then one will have a blockage. You receive a mug later from DeCava to get him a drink. Instead, go talk to Noogie (playing the bongos) and tell him to play up tempo. Quickly use the tube beside him and run to the pool of acid (make sure you aren't too close or it's hard to lock on) and then take the mug out of your inventory and use it on the pool. You can then take the mug back to the blocked pipe, and travel back and forth in it to get the trophy.