I prefer the following method...
1. Replace the capping station sponge with a new one. If you don't have one...remove the sponge and squeeze out as much ink as possible between folded layers of paper
towel and return it to the capping station. (this helps reduce the "Bleed-back")
2. use a large syringe fitted with needle to draw O.E.M. cleaning solution from a cleaning cartridge. (The point of entry into the cart should be obvious)
3. Take one of your little 4"x4" cleaning cloths, tightly fold it in half, then fold into 3rds (6 layers). press it as flat as possible and then place it on top of the capping station
sponge and flood it and the sponge with cleaning solution.
4. With the head height raised, move the head to it's home... over the cap station and lower the head.
5. Let the head sit for 6 to 8 hours.
6. Raise print head and slide clear of station, remove cloth, return head to station and run a few strong cleaning cycles, run test print.
7. Repeat if necessary.
(NOTE): The Black always clogs the most and easiest. The Black pigments seem to be the densest and most likely more coarse. If you permanently loose 1 or 2 of the individual segments of Black in the test print, it will not noticeably affect your prints in most cases.