That formula is home-made Tru-Oil, if their "proprietary" 40% is just varnish.!!!
I once waterproofed a convertible top with Thompson's Water Seal, which seems to be a wax dissolved in diesel fuel. Had to park the car outside for months, it stunk so! But it worked. Twelve years later that top is still watertight.
And yes, all front-stuffers should be browned, never blued.