You could do like Sherlock Holmes and dig out your dottle plugs and let them dry on the fireplace mantel before re-smoking them. 8O But I don't recommend that.
I almost never dump ashes until the end of the smoke. I tamp and relight until I can't get a draft thru the ash table, and then I run the spoon of the pipe nail down the wall to the heel on the OPPOSITE side of the bowl from the draft hole. This creates a new channel that will pull the relight flame aross the bottom and lite any unburned tobac there.
It may take a repeat of this technique until the ash plugs the draft hole and you can't get any draft at all. I then pronounce the smoke finished, stir up the ashes and dump them. I usually have only a few hard black specks of charred tobacco left and no brown, wet, unburned pieces. I will trade a little harshness in the final puffs to get this result. I'd rather burn up any stinky goo left in the heel than leave it there to possibly sour the pipe.
I almost never dump ashes until the end of the smoke. I tamp and relight until I can't get a draft thru the ash table, and then I run the spoon of the pipe nail down the wall to the heel on the OPPOSITE side of the bowl from the draft hole. This creates a new channel that will pull the relight flame aross the bottom and lite any unburned tobac there.
It may take a repeat of this technique until the ash plugs the draft hole and you can't get any draft at all. I then pronounce the smoke finished, stir up the ashes and dump them. I usually have only a few hard black specks of charred tobacco left and no brown, wet, unburned pieces. I will trade a little harshness in the final puffs to get this result. I'd rather burn up any stinky goo left in the heel than leave it there to possibly sour the pipe.