Berryman B-12 Chemtool Fuel Injector Cleaner (part #0116) is not as well-suited for through-rail cleaning as a dedicated cleaner would be.  Instead, we recommend using Berryman B-12 Chemtool Through-Rail Fuel Injector Cleaner (part #1126).  The names are similar enough to be confusing, especially since the label for 1126 doesn’t say “through-rail” as part of the product name.  However, through-rail cleaning is in fact its one job in life.