Yes, that's correct.
@Transform used vodka heated to 60C for 30 minutes, IIRC. I used vodka at room temperature for a couple of hours. It indeed takes only a few hours at most.
I didn't measure it, but it's not necessary to be precise in the amount. The key is to add it slowly, stirring well. You add a bit, stir, add a little bit more, and every so often pause to let it settle. When it's done, you'll see as it settles a transparent yellow layer will appear, you can stop then. If you added more there would be no harm, it's just not necessary. The transparent yellow looks like this (after removing the calcium hydroxide and calcium tannate):
Instant ayahuasca little lightening bolt TEK
I'd leave it a couple of hours at room temperature, but if you heat it up to 60C it seems to be enough with 30 minutes.
@Celly left it in the fridge for a day, and it worked well too.
You can just let it decant and filter the liquid layer through a coffee filter, but it's probably best to do it like
@Celly did here:
Veggie Oils and Fumaric Acid question
In a bain marie / double boiler, which is just boiling water in a big pan, with a smaller pan or container inside where your vodka tincture will be. That prevents you from burning it once the volume is less.
I'm not sure about this, as I have never done it. If the caapi is powdered, it should take less time, but I don't know that for a fact.
Take notes of how much grams MHRB you use, and then the final volume. Then, calculate g/ml.
E.g. if you use 100g MHRB and end up with 50ml, 100 / 50 = 2g/ml. Then calculate the dose based on how much MHRB you'd like to take. In the above example, if you want to take 5g, you'd need 2.5ml.
I usually reduce it until it's only an oily substance with very little to no water, and then add vodka for preservation and to get it to a nice number of ml where I can easily calculate the amount required for a given dose of MHRB.