To clean them, I cut them into pieces but not too small. They really shrink up in the par boiling process. I then put them in a large pot of cold water. Hose them down with the sink hose as I fill the pot with water. Let them soak for about 30 minutes and then swish them around with my hands. I transfer them to another large pot of water and repeat that process. Probably oak them for 10 minutes the second time. After dumping out the first pot of dirty water and replacing with cold clear water, I transfer them again and repeat the process. Might do that 4 times until the water ends up pretty clear. I put a large pot of on the stove with about 4 to 5 " of water to boil. Once it comes to a boil, I put the mushrooms in and wait for it to boil again. Boil mushrooms for 2 to 3 minutes. Dump them in a colander strainer then immediately into a pot of ice water. After the ice melts, dump them in the colander again, then start putting them in quart freezer bags, 2 cups to each. That is how my parents did it and it seems to work for me. My mother used to make the best mushroom soup at Christmas I ever had. Have to try to make it myself this year. Have her recipe but you never know if you give it the same touch. Hope the above helps.