Stressed 'nems don't like to be force fed...however...
If a 'nem is bleached it is not healthy...it will start using itself as food/energy which is why a sick, bleached 'nem whithers away to nothing and dies...just like a person...
So...when they are bleached, you have to feed them at least every other day so that they have something other than themselves to digest for energy...even though they are bleached, there may still be a few cells of zooanthellae (sp) algea left in the tentacles...since the 'nem is not digesting itself for food nor is it relying on the algae for energy it gives the 'nem a chance to maintain itself for a while, while the algae is reproducing itself...
This will eventually allow the 'nem to gain back it's beneficial algae and start using the algae to produce it's energy through light absorbtion...the nem still needs to be fed but the 1x per week feeding is enough at this point...
If you have a severely stressed 'nem and don't feed it, it will do nothing but die...my thread has some pics from someone who bought a bleached H. Crispa and nursed it back to health using this very method...the link was posted previously...take a look...