You can use a shoeshine brush. Or do what most of us do, use a soft cloth… I get comments on how great my saddles look after I have them adjusted - and I’ve never used a brush…
A shoe shine brush has a totally different purpose. This is to get into all the little crevices - the shorter bristles mean even though they’re soft and not damaging they have enough rigidity to do the job.
I have two customs (one Coronado monoflap and a monoflap Monte Carlo jump saddle) and have ridden in many others. I love them