I recently cleaned the sear plunger channel on a Portuguese Army Model 1906 shooter. It was operating just fine, but I find it fun to take apart shooters. My references show DWM delivered this contract around 1909 so the pistol is approximately 108 years old. I found a lot of grime at the channel base and pipe cleaners didn't seem to be doing the job.
A modified Q-Tip helped. The photo below shows a normal Q-tip, the cotton torn off by me, the finished "tool", and the sear bar showing the tight but workable fit of the Q-Tip paper shaft into the plunger channel. Twisting helps. Channel is ready for another 108 years.