Re: preparing tombac with a lack of glycerine
when you start adding herbs and such you no longer have tombac but something else. The method you mention is an approach to make your own moassel. You use tombac as an ingredient in something else but the resultant concoction is not tombac.
In every place you can go to where people smoke tombac they do so with dried leaf soaked in water and coals placed directly on the leaf. It is true that different sorts of leaf can be blended and dried during the curing and packing process and various herbs/liquids can be added to the base but what doesn't change is that tombac means dampened leaf and direct heat.