yes wookie, you may have answered my next question. I’ve just popped down and took the cassette off, axle has been removed using the cone spanners and bearing are all sat in a shot glass lol. but ye a 10mm was just banging around in there. 12mm might do the job.
also agree wookie, I did think cleaning it might not work out, but its worth a try and I need to figure out to take it off to fit a new one anyway.
i’ll try a 12mm later (if I’ve got one! for some reason I think 10mm might be the biggest in the set I use) on this evening, got to go out now. fingers crossed