Digital BW, The Print

So I've just flushed out some junk ink and I want to reuse the carts. These are third party vacuum fill carts with lots of nooks and crannies to hold the leftover water. Short of building a vacuum chamber to boil off the water, what do you suggest? It looks like there is a metal spring for the check valve so I can't stick them in the microwave oven.

I have two more inks and a CIS to install, so I need one set of empty carts to fill (I can use the CIS for the second ink).

And yes I did remove the chips before washing the carts.