I've been using Staticmaster brushes for over a decade as a primary method of controlling dust on negatives. I have found them to be extremely effective. These are the brushes with the radioactive cartridge, and, if you've used them, you know that the cartridge needs to be replaced every couple of years. No big deal. The cartridges for my 1 inch brush cost about $15 (maybe even less) last time I did this.
My current cartridge expires this month, and I went to the B&H site to check on refills. I was stunned to see that the replacement now sells for $65!! Adorama has it for less, but it's still more than $50! It looks like I'll be hunting for a new way to control static.