Itching Powder for the U-Boats

     When American forces were busy liberating the south of France, imagine their surprise when, along a road, instead of German reinforcements, up marched a British officer in full Highland dress, including kilt. Major Havard Gunn had been parachuted in some weeks before dressed in his Seaforth uniform, with his kilt coming down with a subsidiary parachute. From there he joined the French Maquis, or irregular resistance fighters, and no hint of a British officer wearing a kilt behind enemy lines ever reached the ears of the Germans.
     138 Squadron, R.A.F. was tasked with dropping, not only agents, but also supplies into enemy occupied territory. As a general rule, the supplies came down in large, heavily padded containers, inside of which nested a collection of smaller and easily portable packages. At the request of Queen Wilhelmina, sweets and chocolates from the Dutch East Indies were parachuted into the Netherlands as gifts to her hungry subjects. One female American agent operating behind enemy lines - I wish I knew her name -  sent a request to London for certain Elizabeth Arden products, stating precisely the texture of her skin, the colour of her lipstick, the shade and scent of her powder - and the address of her stump-sock supplier, for she had only one leg and the stump of the other one required a new sock. But one of the most interesting items supplied was itching powder.

One British agent got himself a job in a clothing factory which specialised in making the underwater vests for the crews of U-boats. A brilliant and far-sighted idea occurred to him and he put through a demand to London for a supply of itching powder. It was delivered to him some days later.  Before the vests were folded and packed, he sprinkled each one liberally with this powder. His theory was that submarines could not remain submerged for long if the tormented crew were forced to scratch themselves night and day. They would have to come up for air and a change of clothing and, once on the surface, would be vulnerable to attack. This wheeze - it is the right word, for surely itching powder belongs more to the dormitories of private schools than it does on the battlefield - this wheeze worked. One submarine captain surrendered his craft and crew intact. He could no longer remain on the sea's bed, he said, owing to a mysterious epidemic of fleas compared to whose attacks the explosions of depth-charges were trifling. The connection between the award of the D.S.O. and a packet of itching powder may seem remote. Far from it...

Reference: Jerrard Tickell (1956), Moon Squadron, Allan Wingate (pp 122-3 of the 1956 Hodder and Stoughton paperback)

Here's an interesting video about this, and similar tricks.