First day of chem lab Autumn 1958 the instructor with cotton gauze over where his eye had been lectured us on safety.
Whilst swabbing that 10% nitric solution do continue to wear the face shield. Better have it on always. Do not treat nitric acid in a casual manner.
After staining the wood there will still be some acid in it. i recall looking at a rifle in the late 1960's, made by one of the legendary contemporary Maryland makers. The brass patchbox was rimmed in a dull red color. Because residual acid had removed the zinc from the brass. I do not know whether or not he had neutralized the acid, even as a dumb youth I knew better than to discuss this matter with The Master.
And storage. Whatever bottle you have, if you store it long time it will give off enough fumes to rust your favorite whatever (rifle, clock &c) in the vicinity. Don't have a good solution but keep the stuff far away from any fine metal objects.
I don't recall how I liked the finish from nitric. Probably did, I liked to play with such stuff. But do treat nitric acid with respect.