Brian Anderson Gunsmith
I have strong doubts about corrosion being involved as the number of woods that cause dullness includes some that don't appear to have any corrosive properties.
Also corrosion appears to take time on a scale much greater than the appearance of dullness.

We may have avoided including one source of material here , that being our own sweat/blood.
Some human blood can cause rust another form of corrosion. But that corrosion takes time.

No discussion about dullness is complete without a joke.
I have a list sayings and insults...... Please do not attribute this post as an insult to anyone!
"He is not only dull himself; he is the cause of dullness in others." -
Samuel Johnson