Here is Dr. Peat
KMUD: Aging and Energy Reversal (2013)
RP: And there is a little known branch of medicine. I think it was a German who originated it, I think it was called neural therapy, something like that, but it involved finding key points and injecting procaine or other local anesthetic to change the nervous system. And I've seen a great variety of good results from applying any of the local anesthetics topically too. It apparently helps to retrain the memory of the tissue so that it stops producing the recurrent problem such as an ingrown toenail or recurring boils in the surface location. There are a lot of fairly strong local anesthetic ointments sold over the counter. I think benzocaine in the small area is effective and safe but you don't want to use a lot of benzocaine on a big area. The procaine and lidocaine are safer.
I think this is what Dr. Peat is referring to
Absolutely fascinating discussion in this paper and timeline.