Another route would be using dolomite lime. IT NEEDS TO BE PULVERIZED! Sorry, that part is important. This needs to be able to break down in to the soil, and is not water soluble like the epsom. If you get it in any size larger than pulverized, it will not break down fast enough. Even at this size, it will not all break down for a while, well after a single grow. There are a few ways you will find this listed, and may be confusing. There is agricultural lime, and dolomite lime. I think garden lime is just a marketing term, and is either one or the other. This quote is in regards to the differences.
"The primary difference between the two materials is that, in addition to containing calcium carbonate, dolomitic lime also contains a mixture of magnesium carbonate. Typically, the mineral is comprised of approximately 50% calcium carbonate and 40% magnesium carbonate with the remainder being other materials."
The main reason most growers use lime is as a ph buffer, as it has a PH of 7. The best thing if you use this is to let the soil "cook". Mainly with the idea of letting the DL break down and feed the soil. This is cheap also. I paid $6 for 50lbs, but it is from a local source. Will last me longer than my garden will.
I've never used frass myself. From what I understand the best uses are... Feed it to your worms, mix it in the soil, or top dress. In that order. I've never read about making a tea out of it. Does it mix in water, and suspend in it? Does it just go with the flow of the water? (rise with bubbles, but fall right back to the bottom like rocks) If it is able to mix and suspend I would try using it as a foliage spray. Maybe after you learn a bit about FPJ making, add some to it at feeding time.
I also agree with NAN about the gypsum, It is a great thing to condition the soil. Another cheap item that goes a long way.