While sailing round the world in the late 80s, my cousin came across an official in the Cape Verde Islands who clearly wanted some baksheesh to help him do his job. Charlie gave him a pot of Shippam's paste (which in those days carried a Royal Warrant), telling him that it was a gift from Her Majesty. This went down very well indeed, and they were treated like visiting Royalty for the rest of their stay.

Giles. Mogless in Paris.