I use a lot of lye when making soap (about 600 bars a year) and also for staining cherry.
It is very caustic, I have tried to save a stain solution in a mason jar, not a good idea, the metal top rested away quickly. It will also burn your hands on contact. I always keep distilled vinegar on hand to neutralize any spills or contact with skin. Safety glasses or goggles are a good idea as well.
If it's handled carefully like nitric acid it is a great stain.
Kevin
Cherry stained with lye