be carefull with some cleaners.. some cleaners are very agressive, and can pit the metal and cause corosion.. Ive had it happen twice.. it usually wrecks the bearings if they sit to long...
the best way i have found, is to soak them in motor sparay for a few minutes.. then i use an air compressor to forcefully blow them out.. this has worked very well for me.. i dont have to take the seals off anymore either..