food for thought. I would have to buy cartridges though!!
From here I will be checking out laser printers.
Back to square one: your original thought was to "...replace them with all black cartridges."
Why not try your HP with just a single
in the appropriate slot and the color slots empty; could it do anything worse than balk? If it refuses to print with the empty slots you could try with dead color
cartridges in them.
I highly recommend a laser printer; my Canon has been running since July 2013 on its intro cartridge which shows no signs of drying out as do inkjet cartridges.