I found a good spotting technique - accidentally....

I've always used a similar technique, except I use my thumbnail as a pallette and saliva to wet it. Both of which were always exactly in the correct position. The spotting medium didn't seem to be poisonous.
I haven't done any wet printing for many years, photoshop makes it too easy. But, and a big but, I have recently acquired a DeVere enlarger and will be setting up a darkroom in my new house (wherever it will be) and will recommence making proper prints within the next year.