I'm using modified soldering iron with brass tips (from China) in combination with Tandy (Fenice) EcoFlo Proffecional Edge Paint (Section Lacquer). The procedure is: Traditional burnishing (saddle soap/water - not Gum Tragacanth!), than a coat with edge paint. Leave it to dry at least two hours, than apply heat treatment, sand it with sand paper 320, and final coat with edge paint. For smooth effect (like on Hermes stuff), sand it again lightly, rub some beeswax, polish with canvas, rub a paraffin wax and final polish.