I use it all the time as an additive to my 2 cycle mix. Note: If you have actual dirt in your carb, it won't fix that, nothing will other than taking it apart and manually clearing out all the holes.
The stuff really dissolves varnish. Spilled some on a varnished wooden table and it peeled, stripped the varnish right off. Does the same with varnish from old gas. It is soluble in both water and hydrocarbons. Stuff is strange because it smells like Windex. Not sure what's in it (they won't say). It would help in making a 2 cycle mix using E10 a fully homogeneous mixture, because of its dual solubility, then again I only use ethanol free for 2 cycle anyways, and just use the additive as an additional cleaner, conditioner for the gaskets, etc.
Did an experiment with it once where I took half a jar of K1 Kerosene, and added several ounces of B-12 chemtool. The B12 produced all kinds of globules within the K1, as it was mostly insoluble in it, created a separate layer, then added MIB, stirred it and the entire mixture was fully dissolved within itself and stayed that way for days until I no longer needed it (used it to soak a carboned up muffler from some OPE).
Called the company once and asked them if it could be used as a crankcase cleaner added to oil in a 4 cycle engine. They said they have never tested it in such an application, was never designed for that, and thus advised against it. It is not a lubricant, but it's probably slightly more lubricious than B12 chemtool which is probably about as lubricious as water.
It's expensive, but I don't use that much of it so the cost is really immaterial as far as I'm concerned.
