Someone on Audio Asylum e-mailed Record Research about the stiff brush: it's intended to get gross contaminants or dust bunnies off the stylus BEFORE using the actual LP9 with soft brush.
Personally, the short bristles of the stiff brush scare me a bit and I've been afraid of raking the plastic of the brush against the stylus, so I use a Discwasher stylus brush which has much longer bristles, though seemingly as stiff.
Personally, the short bristles of the stiff brush scare me a bit and I've been afraid of raking the plastic of the brush against the stylus, so I use a Discwasher stylus brush which has much longer bristles, though seemingly as stiff.