Not sure what you are asking. The coco holds the water that the nutes are in so technically it does hold on to nutes. If you mean amended like with dry nutes, im sure its possible as Coco Loco is an amended coco mix from Fox Farms. Coco does not have any nutrients in it by its self so yes you have to administer it. One mistake i made when starting out with coco was not buffering the coco before planting and that can cause stunting and efficiencies. Cal mag is your friend in coco. I use GH Trio in coco and follow the schedule on GWE main site as a guide. I feed every water once root system is established and only water when pot is light and water to 10 -20% runoff. I tried the plain water every other watering and ran into deficiencies but that was my experience and know that others have had success doing it that way.
If you want to amend the coco into a coco mix like Coco Loco, i would not water to runoff as that will wash the nutes out of the mix. I personally have not done an amended coco mix grow and just use salt based nutes. Remember, coco is more akin to hydro than soil but it is kinda a mix of both.