The 3-day black garlic technique was developed by Jonny Hunter and was discussed briefly at the beginning of Episode 231. (EDIT: It's actually Episode 237). They've talked about it a few times, but I'm not sure if they ever fully outlined the technique on the podcast. I know that Hunter presented the technique at a MOFAD event called pHDelicious that was about the impact of pH on cooking. So they may have tweaked the pH during the warming step to accelerate the process. I'll see if I can find out more.
What are people's favorite recipes/applications using black garlic? I have a big container of RioRand brand peeled black garlic cloves and am trying to think of new ways to use them. If you're in the market for pre-made black garlic, I highly recommend the RioRand products. The cloves are gigantic, and the fact that there's a pre-peeled option is great (peeling black garlic can be a bit of a chore since it's soft and sticky).