Method for extended technique?

[pianowelsh]

Hi all you piano teachers out there.  Do any of you know of a work book or any particular repertory that can ease students into playing contemporary works using extended technique (ie fore arm and hand clusters, inside the piano work, wind up toys suspended from the lid etc etc. It has always seemed to me that many students are denied the fun of this repertoire because it looks so forbidding and they won't play it for exams or competitions as it simply can't be learnt quickly as they have to come at it cold. If any of you teachers or specialists in extended technique have written books yourself or are inclined to write didactically in this ideom I would love to know.

[mound]

I always thought those types of things were invented by curious/creative/crazy players who simply had an idea and tried something new?