Thinking about a new brush, this time for when I make lather in my Dirty Bird scuttle. Sometimes it's uberlather, sometimes not. I'd love to hear what characteristics others would like in such a brush. I'm thinking a 3 band Silvertip, bulb shaped with a big knot. What's considered big? Over 28mm? Is there such a thing a too big? Anyway, what would you like to see in a scuttle brush?