Yup - Like I said in post 22 - B-12 is Aggressive!! See the video about Berryman B-12 Chemtool I linked in post 22. That shows just how aggressive it is.
Strips varnish, films and gunk right off fuel lines / engine parts / carburetor and injection system internals. I recommend using per instructions. After getting used to B-12 's capabilities then you can begin to play more with varing concentrations.
I had 4bbl carb that set on shelf for years. It was a gummed up mess. In a bucket I placed that carb for 24 hrs. in 30/70 mix of B-12 to gasoline. That was several years ago... still running that carb with no rebuild since. When I took the carb out of bucket I kept dunking it in the bucket fluid as well as scooping out of the bucket and "Basting" the carb for many minutes. The fluid in bucket became dark as heck. Then I flushed the carb with straight gasoline until there was no more color coming out.
yrmv!