It's even worse than you think. If it gets inside of you it will
literally attack you from the inside out. You don't even have to get in
your mouth or breath it. It will absorb through the skin. I knew a guy
years ago working in a plant that used hydrofluoric acid for
electropolishing metals. He accidentally tripped and managed to step
into an open shallow vat of it. Got only up to his ankles as I recall.
They didn't stop the absorption fast enough and it got inside of him.
Literally corroded him from the inside out. Attacked his bones in
particular. Took him a few days to die. What a bloody horrible way to
go. Made me sick to my stomach when I heard what had happened to him.
If this pickling material does contain HF then be VERY careful. There is
a special cream you can get if you are working with HF. I think it's
calcium gluconate. If you get any HF on you get this cream on the
affected area ASAP.

Sorry I cant give an answer to your question about the smudging, but
please be super careful with that pickling paste. It may contain
hydro-fluoric acid which is shocking stuff if you get it on your
skin. Look up the material saftey notes on it. Please be careful with
it.