Tadgh, hydrofluoric acid is a contact poison. It is absorbed through the skin and is highly toxic. The fumes are equally toxic.
Is using that a good idea?
Hydrofluoric acid dissolves oxides and silicates and provided the lead oxide hasn't chemically bonded to the glass to form lead carbonate, it will dissolve it. As there's silica (sand) in glass, if left, it'll dissolve that as well.
Virosol etc will only be as effective as almost anything else like Mr Muscle, etc. An abrasive substance will remove anything that isn't bonded but there again, so will a stiff brush and water. Lead compounds are a whole different kettle of fish to organic dirt.
I only know that as I once thought to get into restoring really old stained glass but after going on an introductory course before laying out a lot of money, I changed my mind because of some of the chemical involved.