I bought a set of 8 bags from amazon I think. It was not the name brand bubble bags, but they have been perfectly functional, no problems whatsoever. I can look up exactly what they are if you want when I get home. It was the 5 gallon set. I think it's a bit of a pain in the ass to deal with 8 bags, especially since the difference in grades between the sizes doesn't seem to be much. I don't even like smoking it all that much. My weed is high enough quality that I don't need the hash, and smoking a whole bowl of hash fucks with my sinuses and throat - it's too harsh and smoky. It does get you ripped though. I don't separate by grade anymore, and I use it exclusively for cooking.
I use the smallest bag, the 2nd largest, and the largest. Put smallest bag in bucket, followed by 2nd largest, then largest. Alternate layers of ice and pre frozen trimmings or bud (already chopped/ground up). Fill with water (ice will float, so don't try to fill above hash/ice or you will overflow bucket). Use a paint stirrer attached to drill for about 5 minutes to stir the shit out of it. Remove top 2 bags (don't dispose of material). Remove 25 micron bag (you will need to agitate violently. Hash will settle on screen and block holes not allowing water to drain. You need to shake it up to fluff the hash off the screen and keep it from settling). After all water is drained grip wad of hash from underside of bag and flip the bag inside out. Spread the screen/bag over a bowl or something so you can scrape the hash off a taught screen. Place hash onto your 25 micron non-bag-screen they give you, and fold it over on top of hash. Place between layers of bath towels and compress. Remove hash and place on card board to dry. Replace bags and repeat procedure to get more hash out of trimmings. I only get about 25-35% of total yield from the first run. I usually run through the process about 7-10 times, or until I think further effort is no longer worth the diminishing yields. I recommend breaking hash up into a powder while it's still wet and leaving on cardboard. Once it drys into a clump it is very sticky and tends to have the consistency of tar - very difficult to evenly distribute in baked goods.
I use the final product in peanut butter cookies. about 3 grams into 1 package of betty crocker peanut butter mix. Mix dry hash in with dry cookie mix, then add other ingredients. Cook about 25-50*F less than package says, and for a few minutes less. Cookies will be undercooked, but will dry and solidify. Yields about 25-35 cookies depending on size and will fuck you up good.