Thanks for the pointer to the article, Cozmo!
It reads as a a normal result of the release of secret documents, under the 'XX' year rule. There's usually a few 'gee whizz' bits in there. However the facts, as known match up once you strip the hyperbole.
Britain, like most countries experimented with chemical and biological warfare in the 1930s (those 'smoke laying devices weren't all for smoke) but didn't pursue it. In W.W.II all the major combatants stockpiled various chemical and biological weapons and there's a few traces of anticipated uses - defensive or offensive if you look hard.
A famous example of wartime tests was Gruinard Island:
http://en.wikipedia.org/wiki/Gruinard_Island
I like the bit about 'abandoning' the idea in 1945. Well, yes, they were very definitely winning with the other weapons!
In W.W.I 'flechettes' were small weighted darts like sharp finned bullets, mostly, and thrown out of aircraft as they crossed the front line or a convoy. Given the horse drawn nature of the armies of 1914-18, they had a bigger target than just men (with helmets).
The AW Whitley, seen in the pre-war pic with Tiger engines, rather than the more common, later Merlins, was one of Britain's heavies in 1939, along with the Wellington. It was used extensively by Bomber Command initially for 'Bumpf Raids' - dropping propaganda leaflets and they flew as far as Berlin to do so. Obsolete, it was used later in Coastal Command against U Boats and was the main type used to develop the paratroop drooping technique through the ventral hole where the ventral turret had originally been fitted.
Leonard Cheshire started W.W.II as a Whitley pilot in 1940 and was an observer in a B-29 at the dropping of one of the atomic bombs - five years of the bomber war.
Group Captain Geoffrey Leonard Cheshire, Baron Cheshire, VC, OM, DSO and Two Bars, DFC
http://en.wikipedia.org/wiki/Leonard_Cheshire
He would probably point to his postwar work as his greater achievement.
Just some thoughts.