I wouldn't have any problems with the actual painting part, but I would have problems with the spray...
I once tried a matte spray on another figure... It was a mess, i was not able to apply the spray in the particular zone i wanted and it spilled all over it...
How would i be able to apply it only on the eyebrow, and avoid it being spilled to areas?
And even the spray wasnt very matte, it still left the figure very shiny...
I have already painted the eyebrow, i used a carbon based pencil... Its very dark, but once you put a light on it, it becomes very shiny... Like i said, my problem is getting it to look matte...