I've used Ilford Warmtone FB almost exclusively for a few years now, and I spot my prints with Spotone, too. I usually mix No 4 + 5, as it matches my developer and toning sequence, but I've used other colours too. I've a few prints with deep blacks that need a "touch" of spotting. I'd never use dried Spotone while spotting. I have it diluted, in three shades, and using the darkest dilution, in this case, I apply it, wet, but using an almost dry 00 or 000 brushes (wiped over a paper towel). I apply it repetitevely, using a stippling motion, to build up the tone. At first not much happens, but in a few minutes it starts taking the tone. It will go as dark as the surrounding area, but it will take a while, maybe 400-500 touches wth a brush. I've a print that takes 3 hours to spot, but I'm told this is not as bad as one of a friend of mines, which takes her 7 hours!