Using worm casings

I am going to use a coco and worm casing tek to grow with. My question is there a % that applys to the worm casing loss after steeping it in water. I plan on using 2 quart jars and was curious what the loss ratio will be. To do all of my jars I am going to need 20 cups of worm casings. I have 2 1 qt jar knocked up right now and plan on using it for grain to grain transfer into my larger jars. If I knew the % of loss I would only have to steep 1 time. Thanks for the info

Why steep the castings in water?

it was part of the tek I read I didnt know if you could just sterilize in the oven wich I prefer to do.

don't sterilize it, just bake it at below 170 and above 160 for a couple of hours. do it at field capacity of course.