That's right. Our's would have lasted longer. We added 18" to our overhanging eaves about 7 years ago when we moved our log cabin and re-roofed (first time re-roofing in 34 years.) Keep the direct weather off and it will last a very long time.
From another post of mine,
We make chinking with flour, here is a picture of our poplar logs and chinking, from another post.

Double Tree on varnished poplar logs, near stove. Chinking is 1/3 sawdust, 1/3 flour, 1/3 lime, insulation is moss.
This is from further on in that post, about mixing chinking,
Depends on how you mix it. After a few batches you get the hang of it. You have to mix it dryer for bigger spaces; mix it wetter, even a little runny, for smaller cracks or finishing. I have used caulking recently, when to lazy to mix a batch to seal off an area outside which I didn't like the looks of. But I should have mixed up a batch, because it last longer.
Inside, when it's varnished (only was varnished for the last five years -- before that no varnish) it will last (I want to write forever, of course that's not true) a long time. With good roof overhans it will stay dry. This fall, as mentioned, for the first time, we have added a stain-sealer to the outside. That should seal the chinking and help keep it even better.

That's me, with lime in the blue bucket, flour from the yellow bag, some shavings on the ground. Then you mix it with water, about like the mentioned dough, or thinner, depending.
Have fun, give it a try, you can always change it, if you can get it out.
Alex