I bought one of the ink refill kits and use the syringe to put a few drops of water in the cartridge. I can go for a long time before refilling with ink. I use the same cartridge over and over for so long it quits working before the ink runs out.
I've gotten so good at refilling I don't have to wear gloves and do it right over the printer, takes me about a minute to have it out and back in.