I've learned that the airway is where most of the ghosting happens. And if a pipe goes awry or sour, it's probably in the airway. I personally only use q-tips like a plugging device. I feel there is no substitute for a tube scrub brush and soap. I've told this story in the past, but I had an estate pipe that I could not get to stop ghosting in the final 1/4 or so of each smoke. The first 3/4 was so-so, but that final 1/4 was terrible. It had gone through my old process TWICE of alcohol and bristled pipe cleaners and an alcohol/cotton balls soak. I was planning to sell it. It really frustrated me. But before I dumped it onto someone else, I was going to use it as my experimental pipe with running water, dish soap, and a scrub brush. It pissed me off so much that I didn't care if I ruined it. 5 minutes with soap and water, and it is now one of my best smoking pipes. I haven't had even a hint of that ghost since. I was so pleased that then I also used a green scrub pad for dishes on the inside of the bowl and gave it a second scrub brushing while I had it wet a second time.
Back to the q-tips. I shove it in there so good, as a plug, that I often have to use a metal poker to get the cotton out of the airway.