I found this out by accident using egg yolk, pine soot and brick dust to paint some brain tan. Me thinks, suede could be similar. If Mr. Burrow's walnut dye works, well...we are talking same general type.
I painted designs on some braintan; red and black. Was not satisfied. Problem being...my braintan item was done! Cart before the horse? So what to do? In a fit of despair, I take to the sink when Momma is out and run under the hot water sprayer at the kitchen sink and use one of her old toothbrushes she keeps around for cleaning and...brushed it off.
Looked terrible! Oh well, start again.
No!
After it dried it looked like it had been around for half century or so!