Mounting bookshelfs flush with ceiling - can you?


Instead of the standard true ceiling speakers for the surround channels in a 5.1 system, has anyone ever tried just mounting a bookshelf speaker flush (totally recessed) with the ceiling via attic? One can always buy a white speaker grill to cover the area in the ceiling. I imagine that a bookshelf in the $250 range (used) will sound better than a true ceiling mount speaker in that range.

Ideas? or am I way off on this concept?
goldenears7
Tall stands, save yourself cutting through plaster. If you can't buy them the right size, find yourself a welder to cut up and weld a pipe stand with  a tripod base, maybe?
Post removed 
baffle step, right on the money.  
ceiling or wall speakers are best.  
for the application.
encposed speakers can work well near the ceiling on brackets but not flush.