My z3100 started to leave some unexpected black spots on prints so I did a typical cleaning that included
Removing each print head and cleaning with distilled water and q tips, but one can use lint free towels or even coffee filters.
Next I cut the heads off of several q tips and used forceps to get the q tip to the location where the print head passes through the bottom of the carriage. I wet the q tips with distilled water and cleaned where the print head fits in the carriage, plus around where the print head pokes through the carriage bottom. I did this until the damp Q tips came out clean. After that I used several dry q tips to finish up and remove any left over water. This took quite a while as Its been about year since the last cleaning.
Another way to do part of this is to remove 2 print heads that are side by side and loop a damp lint free towel between the 2 openings and move the towel back and forth to clean out stuff between the 2 openings. This approach will only clean the sides, however, and the front and back also need to be cleaned.
Next I did a cleaning of the carriage docking areas on the left and right, using lint free towels and distilled water, and removed all the ink I could see.
After that I used air in a can to blow out any dust, canvas, cat hairs and other debris that could be removed. I did this from the top of the printer, plus the front and back.
After that I printed head alignment test and a couple of test prints to make sure all was okay (it was) and now I won’t need to bother with it until the carriage starts to drop ink again.
BTW, get some exam gloves from Costco and use them during this process. It’ll keep your hands clean but most importantly, it will make it nearly impossible for your skin and the oils and other stuff skin carries to contaminate anything in the printer.