Need to be a lil more specific. As in do you still use a tincture to make poison? yes.

May your pockets always be full and wrists chainless

The last few times I cooked, I had some trouble with the tinctures. Sometimes it doesn't seem to work, and I was not able to pin down exactly why. In those cases, I got things moving again by starting with fresh ingredients and new jars - they are still sold in some shops and I can verify that they do work.