Hash is still THC, and THC is fat soluble, so yes the procedure is basically the same. I usually only use hash when I cook. I use about 7g of strong hash per 50 edibles. I find that hash is particularly suited for a slow cooker, as the oil slowly warms up, the hash melts perfectly.
I put the hash into the desired amount of oil for the amount of edibles you're making into a slow cooker and cook on low for 12-18 hours, the longer the better, mixing every hour at first until the hash is completely dissolved, then every 3-4 hours until complete. You really can't cook it for too long on a slow cooker as it never reaches a temperature high enough to burn your active ingredients.
Your cook time could be a little lower with hash as it basically melts into the oil so you get maximum surface area compared to using ground bud, but I still cook for 12 hours with bud or hash regardless to get the most out of it.
Strong hash edibles are going to give you a much more "psychedelic" high and are great for pain relief and sleep aid (going to be strain dependent to a certain point but hash in general is great for pain and insomnia).
I'm in the process of making some oil in the slow cooker right now, 1 cup oil (24 edibles) with 3g kief, 14g Sour Diesel and 1g of BHO. I'm going to be putting up a thread tomorrow explaining a step by step all the way through the process after I finish the oil and bake the brownies if you want to look for that.
