Tintin and the Picaros: Part 2 - S2-E9
Plot hole: When the helicopter flies over the jungle, Haddock inadvertently walks in view of the helicopter and the pilot of the helicopter notices him, assuming it to be a Picaro. Haddock then trips into the river, but despite being watched by the pilot of the helicopter the entire time, the helicopter pilot doesn't notice him falling into the river and instead assumes he just disappeared. (00:26:20)
Chosen answer: It is a pill that makes alcohol taste disgusting.