This last time out on the job, I took seven pipes with me.Smoked each pipe between one and two times per day.After the day is over, I cleaned out the shank and stem with grain alcohol and let it rest for a week,untill it's next turn.This went on for six and a half months.They recovered OK for the first three months,but when I got home they all needed a long rest.Even with cleaning and a week's rest,they still had a noticeable rankness about them.They are still resting as I make this entry, but now they smell well aired out, almost.Should have had fourteen pipes, but due to space considerations I had only seven.And I was smoking a somewhat dry tobacco.
Hope this gives you some guidance.