Humidity is the key. I hang my film to dry in a basement that is cleaned maybe once every two years. It isn't a furnished basement, but just one big room with a 100 year old concrete floors, stone walls, no direct heat, and lots of spider webs. The cats' litter boxes are down there too, and they do jump up among my photo equipment in my 'dark corner' that is my darkroom.
Also, I use Sprint wetting agent (has an anti-static quality to it) at the end of the process, and wipe off excess fluid before I hang negs to dry, and I never have a single speck of anything on the negatives. Always perfect, and very little spotting done when the prints are finished.