the best way to clean bearings is in a small container with lighter fluid. Swish them around and watch the crud comeout of them. air dry or blow dry them. spin on a pencil or screwdriver shaft, if they spin freely, you are good to go. then apply one drop of oil. If they do not spin freely, re-soak and start the process all over again. You should be able to put them to your ear and hear them zing. The trick with bearings is the maintenance and if you do not remember anything else, remember this, one drop of oil per bearing. too much oil will cause the internal balls to get boged down in the oil and not run freely around the raceway. TG'S Rocketfuel in the Yellow is excellent. However, if you prefer some other kind, try it, but remember, one drop. we use a toothpick or syringe. If you can't get bearing off a spool due to a pin holding it on, squirt lighter fluid into bearing, prop it up, soak it and empty it then air dry or blow then spin and oil. same process, but removing pin can be scary. if you bend the pin, you wll be buying new spool. We remove pin by using a small ball peen hammer and gently holding spool, tap out the pin. Carefully. Good luck.