Digital BW, The Print

I'm trying to resurrect an Epson R200. Somebody gave it to me but it's been sitting for months with no carts installed. So I'm sure it's pretty badly clogged.

I want to set it up like my R220, as a backup. In my R220 I do BO printing with an Eboni cart in the black position and MIS cleaning fluid in the other positions.

I plan to use Windex (or Simple Green? Is that better?) in the cleaning process using suggestions from Art Entlich's excellent Epson manual. But how I do know when the nozzles are clean? The black position's status will be obvious but not the others. Should I slightly tint the others? with what? I don't have any color ink on hand. Shall I put a drop or two of the Eboni in each cart so I can see if those nozzles are clear?