There have been several TV documentrys that covered this. The book Saturday at MI9 by Aiery Neve, makes some references to such things but at the time methods were still 'Classified'. I belive the SOE special kit manaual is now published. Exploding rats and dung are amongst the range available to the discerning sabotuer. Dick Strawbridge demonstarted some of the bizzare designs in his TV series. One of the more simple tricks was the supply of 'Housewife's to prisoners (For those not familiar the Housewife or Huswife is a generic term for the military issue sewing kit, I was issued one in the RN in 1972) At least one neddle was magnitised, float in a puddle of water, instant compass. As a matter of intrest, RAF officers are still exempt from search on MOD sites, the original reason was they could have been carrying escape maps, escape route details and tools, the existense of which where considered 'Most Secret' (Top Secret was an American designation)