I reuse coco for 4 to 5 plants
let it dry out, from the Underside dig from the middle spreading the root ball, use a spray bottle with water to mist the air and coco as you separated. When you feel you have gotten a good amount throw the root ball away, turn your coco pile and remove large root clumps, I have found that you are beating a dead horse at a point and adding new coco/perlite to your old mix helps replenish and renew without the frustration of digging to a lot of roots out.
if you flush your plants at the end of a grow with plain Ph'ed water you can go right to the next pot.