There are a class of chemicals called "biflourides" which are one molar portion of a soluble fluoride and hydrofluoric acid combined. They are solids, don't release HF vapors unless heated, and can be made into solutions/ pastes and painted onto the glass in question. They are still very nasty compounds, but not nearly as dangerous as HF and are the active ingredient in "Armour Etch" glass etching cream, nothing more than sodium and ammonium bifluorides, water, and titanium dioxide powder to make a paste.