I also use Gir's tek and I can confirm it works wonderfully. Not so much with the shredded bark, though. I used this tek and I got about 40% less DMT from the shredded bark than from powdered. The difference with powdered is, you need to do a wash or a freeze evap. With the shredded bark you can get away without the final step, to the detriment of yield loss.
Remember to heat the naptha before each pull, by placing the naptha into a [open lid] jar and placing the jar into a bowl of hot water. Something between 25 and 40 ml of naptha per pull is more than enough, me thinks. I like to use 35-40ml, just because it's impossible to get the last 5ml or so from the solution. Other than that, just scale down the materials and you should be fine.
Just a few insights from my own experience. Welcome and good luck!
The truth...lies within.