FWIW, I agree on Acraglas especially on hidden tangs. I prefer Acraglas gel for scale handles. Acraglas pours like syrup while the gel has more of semi-soft butter consistentcy. I still wish they mfg'd Acraweld, it was my favorite.
I have the marking methods 300 machine, msc1 electrolyte and ernie's stencils. Using the hand pad. One tip I would offer is to hold the positive down on the stencil for a two second count and up for one second. Etching for longer periods without lifting the q-tip will and can produce halos...