I use a pig-hair brush after every wear. They look great after lots of use. I've tried all kinds of erasers and brushes over the years. The metal brushes are too harsh, but the synthetic nylon brushes are sometimes too soft and ineffective. I don't use the protective spray, but I'm sure it will work fine. ( I actually have a bottle of that Saphir branded stuff someplace.) Something about spraying chemicals onto it doesn't seem like it's a great idea--over time.
The forum needs pictures.
The brush the SA sold me is a hybrid of nylon on the edges and brass in the center. Seems to do a good job, but I will look for a pig-hair one. Thanks for the advice.