Epson PRO 4900 one color completely out

Epson sent me a new LK cartridge, but after a half dozen powerful nozzle cleanings on the LK nozzle, still nothing.

I've tried printing a few completely greyscale photos, then clean, then check.

No LK nozzles print.

If I just wanted to print something that ONLY used the LK ink, how would I do that? Is there a "%" black that if I fill a page with it, the printer would only use the LK cartridge?

Epson wanted me to empty the new cartridge with cleanings and prints, but that'd take days at the rate this printer works.

Next step, I suppose, is to call Epson back and request a replacement.