Digital BW, The Print

I know there's been a fair amount of discussion of this question, but
usually in the context of some other issues, so permit me start on a
specific thread on this.

Am about to spring for a refurbed R1800 and use Paul Roark's 3-MK
approach. I'm accustomed to using MIS' refillable carts for the black
position in my R220, with cleaning solution in the other five. Am
using MIS' Eboni ink with great results on smaller prints, very
pleased with the prints. Thanks to Clayton Jones for this simple and
effective way to get started in B/W digital printing.

But what now? I've heard about Efillink carts but they don't sell them
empty... you'd have to buy them filled, then flush them out, right?
Because you wouldn't want their ink to mix with the Eboni.

There's there's this approach:

http://www.rjettek.com/catalog/product_info.php/products_id/486

I saw some comments on this a while back, but not much lately. Anyone
tried this recently? Apparently you can use the OEM cartridge and fill
it in place. Then there's no need to chase down an empty refillable
cartridge somewhere. You'd still have to flush out the OEM ink however.

Thanks all!