I don't think it's snake oil..
Too many credible folks have looked into it. I think it was the Stanadyne folks who did the lubricity testing that showed 2% mix in regular fuel restored lube properties of the fuel. Sounds like running 100% is fine in addition to making the motor run smoother etc. It sounds like it does keep the tank etc nice and clean but I gotta admit, it was the 60 - 70 cents a gallon that was catching my eye :) . I didn't know that the glycerin byproduct was biodegradable. My boss said that the trash collection trucks in his community are running this stuff at 20%. Don't know whats up with the volkswagon diesels, maybe they have sensors or electronics that its unfriendly towards.
I did this at work a few years back with an algal DHA rich oil and the process is simple and straight forward, wish I would of known I could have put the results in my tank.
Brian on Old Blue out.