I've only used it a handful of times, making a compost tea with Oregonism, molasses and earthworm castings. I aerate for 2 days in a 5-gal bucket (gets really foamy), then dilute maybe 4:1 and water it in. I use it for all my plants - mj and veggies/houseplants - maybe once a month or so.
I've also recently added some to a batch of supersoil I made up, but it's still cooking so I haven't tried using it yet. I used maybe a quarter cup to 6-7 gal supersoil. I don't really think the exact amount is that important, but I do think that the manufacturers' suggestions are too high (esp. considering how much it costs). If you make a tea with it and aerate for 48-72 hrs (adding molasses in portions along the way), you should be able to generate A LOT of beneficial bacteria using a relatively small amt of Oregonism powder.