There are many ways to clean your printer, and some procedures are easier with some models (such as cleaning the print head with a desktop printer model), but Epson inkjet printers have the same primary parts, and all printers should be cleaned/maintained for the best quality output and longest life. There are many factors when deciding what part or how to clean your printer, the main factor being: what's causing the problem. You don't always know the cause, but can troubleshoot and rule out possibilities to help narrow down the cause (sometimes there are many things together).
If there's a chance this channel isn't printing because the cartridge ran dry and air got into the ink line, then I would recommend starting by doing a few power clean cycles or an initial fill cycle to try purging the air, or print pure ink from that channel using QTR's Calibration Mode. As I have told others, we have received reports from a few customers who have had success using the print head cleaning kit in the cartridge chamber of their R3000 printers (against our recommendation), but this concerns me for many reasons (the risk of causing more damage is high). In those situations, I am not certain if the issue was dried ink in the print head channel that restricted ink flow of that channel, particles or air in the damper, air in the ink line, or what exactly was causing their issues. I am very happy this fixed their issues, but also feel like they're lucky to have had success instead of suffering the damage that could have occurred. Either way- I have done some testing, and want to do more to learn better how this effects the printer before writing a procedure or recommending doing this to a pro model printer. I have told a few people about others' procedures and success, but always caution that damage could occur and I haven't tested this thoroughly myself.
I hope this helps clarify my response, but please let me know if I have confused you more, if you have further questions or there's anything else I can help you with.
All the best~ Dana