When bearings show signs of surface rust then i would recommend they be discarded rather than cleaned. What normally happens the race becomes pitted or the balls you cannot see it but when cleaned and casted it will be rough or noisy.
Any of the bearing suppliers can provide you with replacement bearings, however please remember you get what you pay for use ONLY good grade stainless bearings in the reel and on the spoolshaft specifically.
Also then try to use only synthetic oils and grease inside your reel there are a few available in our tackle stores.
I actually find that the ceramic bearings dont seem to last longer than good grade stainless ones for some reason, the ceramics i also find seem to make the reel feel courser when working, the Abecs are ok but stick to abec 5 anything over that and distance will suffer due to closer tolerances.
But rememeber the golden rule use whatever works best for you.
Hope this helps a bit.
Regards.