Thanks for the tag, cbd.
My teas are essentially all anaerobic ones these days, following the Jadam methodology and they couldn't be easier. Just add castings to some non-chlorinated water and go to town. I don't add bubble stones or anything.
You can add the sugar source as
@cbdhemp808 suggests if you want to try to multiply the microbes over time, but you can also use it immediately as the water will help dissolve the goodies and get them dispersed further down into the container.
Topdressing with a healthy amount of castings is also something I do, and that way each time you water you are sending some of the worm goodness down into your soil. And by healthy, I mean that I use
a lot. I've been known to put a layer of an inch or so on top of the soil with positive effects. Fresh castings sitting on the surface like that will dry out to a concrete like consistency so they need to be covered with a mulch layer to help prevent that.
Edit:
Ok, I just read the thread from the beginning and that looks like a classic calcium deficiency to me, which is also far more common than a boron one. If so, the castings would help a lot since they come out of the worm covered in a calcium carbonate slime before they harden into what we call castings.
Also, as cbd says, depending on the feed source to the worms, the castings will have all kinds of other beneficial nutrients all in a plant available form with extra microbes for the soil. So I'd start with the castings to solve what looks to me like a calcium issue, but they bring along so much more to help with other things as well.