I have used Lubegard. The first time I ever tried it my engine seemed to run much smooter. I don't know how it compares to Auto-RX but Lubegard is supposed to consist of 'liquid wax esters.' So it is an ester product like Auto-RX. The liquid wax esters in Lubegard are supposed to be nearly identical to liquid wax esters that used to come from Sperm Whales. But the Lubegard esters come from plants, like Rapeseed. There was a famous chemist who used to work, I believe, if I remember correctly, for Exxon or Mobil, who was involved in the development of Lubegard. And the Department of Agriculture apparently helped because Lubegard is a product that comes from plants.
It is easier for me to believe in a product like Lubegard then PTFE additives and this other stuff you hear about. I know for a fact that Lubegard for transmissions used to be common in many automatic transmission shops. I have not seen the engine treatment as much.
I don't know what the situation is like today. But I know that you would be able to find Lubegard for transmissions in many automatic transmission shops in the past. It was a common sight.