Dykem layout fluid is available in aerosol form and is more durable than Sharpie marker. You'll need to rinse the cases in acetone or brake cleaner to remove it, unless you're wet tumbling.
Neither will actually dye or stain the brass though. They do not penetrate the material at a microscopic level like say, the way anodizing penetrates aluminum, so you'll have to make applying either one part of your loading process, every time.
