Digital BW, The Print

Can the CIS cart chambers from MIS be cleaned out if you want to 
change from one MIS ink to another?

I had an incorrect inkset delivered (2 of the 4 inks - C&M), and the 
2 incorrect ones are going to be exchanged, but I'd already started 
filling the carts (vaccuum method not bottom fill).

I've not yet installed and punctured the bottom of the carts.  

One can suck up most of the ink by pulling it back up the tube with a 
syringe - what about the rest ?

Is it more viable to just mix it with the new ink and "print it out" 
until exhausted ?

And can the tubing be flushed and reattached to the cart ?