Results will vary depending on the mass of roots in your container. For instance, I use 9X9's (2.5 Gallon) and when I finish a longer growing variety, the coco is chuck full of roots. I find that in this specific scenario it just makes more sense to compost the used coco/roots. The time it would take and the amount I would reclaim just wouldn't justify the efforts in this case. Fortunately, you can compost your coco/roots and then use it for compost teas or soil later.