I don’t print any abrasive materials at all. Pretty much only normal PLA and PETG.
I noticed, that my print quality gradually went down quite a bit, especially in the last few prints. I had a lot of stringing, weird blobs, and scarred surfaces.
Now, the print quality is as good as it should be!
They are dirt cheap. You can get a set of 10-15 generic ones, in different sizes, for only a few bucks. Don’t forget that they are consumables.
And if you do print aggressive abrasive materials, remember to either get a super expensive hardox nozzle, or just throw them away after each print. Woodfiber will murder any nozzle.
Gotta say though, your nozzle mostly looks dirty, not worn out (much)
This solution to abrasive filament is a tungsten nozzle or one of the ruby tip ones. The cost is a bit expensive but with a tungsten nozzle you might be one and done
Forget about tungsten, get yourself a Diamondback nozzle They’re pretty much indestructible regardless of the hardness of the filament! Ask our boy Zack over at Voidstar Labs
Periodically, not sporadically
Change your nozzle randomly and without warning