Hmm...you might get lucky, but honestly you'd have much more success using blood + bone etc in soil, where it can break down, spread out, and be utilised and taken in by the plant fully. Coco won't break it down or let it leech throughout the medium like soil will; it'll kinda just keep it there, and if it begins to leach, it'll get washed out when you water to run-off (which you need to do to keep mineral salts down in your coco).

Coco is far closer to hydro growing than soil growing tbh; I've used it for years in terms of regular horticulture and found that when you use it properly (with coco nutes), it's the best of both worlds in terms of yields and ease of growing. If not done ideally (using regular garden/soil nutes), it'll be a bit of waste of time and probably really disheartening (you'd yield more in soil with blood & bone than in coco for sure). Roots spread through soil and live and grow in it, taking part in a much larger cycle of microbiology (where things like organic matter really do help). Coco is basically just structure that holds your plant upright, and can take in water and nutrients that your plant sucks up. Organic matter just makes things complicated, and can lead to more issues than it's worth.

RE: runoff, I've never bothered, but that's because my medium is totally inert (only coco and perlite). Therefore, if I feed at 6 and to the point of a little bit of run off (water starts trickling out the bottom of the pot), I know that all the coco is soaked with fresh nutrients, at the right amount, at the perfect ph, and any left over mineral salts from last feed as washed out and replaced. Run off is then irrelevant. Has always worked for me!