Hi! I recently bought a De Buyer Mineral B fry pan and have been seasoning and using it. While the bottom of the pan has gotten darker and feels smooth, the sides tend to get a kind of sticky grease residue that does not feel smooth. Is that part of the seasoning? If not, how can you avoid it or get rid of it without stripping the seasoning? Can anyone describe what proper seasoning might look like (or have a close-up picture)? Thanks!!