So this lovely Estie that I was given has been clogged and I have not been able to get it to write for a number of months. It had been leaking a little bit (which I ascribed to my inexperience with eyedropper-filling a used cartouche), and I had put a bit of silicone grease around the places where the body connects to the nib unit. Then I couldn't get it to write at all.
Usually, when I am doing my pen maintenance, I will fiddle with it a bit. Yesterday, on a lark, I placed its nib on a paper towel that I had just used to blot up a bit of ginger tea. Although I had previously tried capillary action, for some reason this time the ink began to flow again.
I don't know if it was the ginger, time or something else, but I am quite grateful to have this pen working again as it is a pleasure to use and had been very reliable.