If you are halfway through My Arm's Big Adventure quest or have completed it, you can obtain Ugthanki dung by talking to certain Camels (e.g. the one outside of the Al Kharid bank: Al the Camel) while having the Camulet equipped. Eventually, after talking for a while, Ugthanki dung will appear on the ground. Use a bucket on the dung to place the dung in your inventory. This method can't be used during The Feud. This method may take some time, it is recommended to use the red hot sauce instead.