Got a dozen knackered turbo's. Chipped ceramic on some, some don't appear damaged on the ceramic but either fluff out or fire pencil jet. Easier to just buy a new one at £28 each.
I prefer the black one's that wash down supplies sell, also bought local same price.
The blue 250 bar one's from my experience break faster.
Going dearer than £28 I've use Suttner turbo's (£65ish), had two. Great output but both broke faster than any others and the repair kits were £40.