cleaning clogged lines on Epson 7600

Hi everyone, got a 7600 cheap that has ultrachrome ink. Most everything on the control panel got 5 stars. Did multiple head cleanings, a power cleaning, and puddling of the cap and paper towel trick on the print head. I've only got one black working so far. I can see that the yellow line is clogged, and I'm guessing the rest may be as well. So any suggestions on clearing the lines. There are a lot of options out there, do I pay $200+ for cartridges with special fluid or just get refillables for around $100 and fill them with simple green. I don't know if the original users switched ink types, so there could be gelling instead of crystaling in there. Thanks.