Yes, too much trouble. I experimented filling up my HP deskjet cartridge, which is probably one of the more accomodating cartridges to try to refill. The results were unreliable and a lot of trouble. More ink went down the sink than was printed.
My recommendation - order some refurbished cartridges off the internet. They are more reliable than refilling them yourself. However, they're still refurbished by a third party, so they're not the best cartridges in the world, but if you use them constantly, it's a possibility to explore. Just search Google for refurbished ink cartridges.