No, not unclear, just clarifying.
So what kind of products are more heavy weight? The reason I ask is because the dirt you can't get out with a leather cleaner isn't because it hasn't worked but because the soil has tarnished the colour, just as it does on fabric upholstery, or a traffic lane on a carpet. So surely if you've got the leather as clean as it can be got, but isn't perfect, where chemically do you go next, because I thought restoration of the colour would be the only solution.
Simon