Not sure where you got the idea detritus dossent feed some corals. Detritus feeds many SPS corals.
Agreed! detritus stirring was one of the orginal methods of feeding coral! detritus isn't just fish poop/decomposing organics- key word there decomposing= bacteria, corals will also feed on the bacterias as well as the poo!
Peter Wilkens first started doing this back in the late 70s/80s in Germany to successfully keep non photosynthetic corals like dendronepthya /sclecronepthya (spelling?)
I think there is even a picture of him doing it in one of the Julian Sprungs book series if I remember correctly.