how about approaching a local nursery and asking them to donate a few
out of bloom plants? one of my local places sells them for ten bucks,
but then i don't know what they do with them if they don't sell. i
somehow doubt they're going back to the orchid growers. maybe a local
place would give you a handful to experiment on in exchange for a plug
for the store during the demo.

(and yes--people *love* to bring in their own plants in the hopes
someone else will repot them.

--j_a