Giving the gopher repellent to Otis

To give two items in a row to Otis, start by giving him the breath mints and, while Guybrush walks to Otis' cell to do so, open the inventory, press the down arrow key so the gopher repellent gets surrounded by the yellow box, and close the inventory before the conversation with Otis starts. This way it'll be easier and faster to give him the repellent once the conversation is over.