pop bearings out, remove shields, chuck in a sealable bottle with enough citrus degreaser to cover the bearings. give it a good shake, leave for a few mins and repeat that a couple times. take the bearings out, rinse under water and shake/dry em off with a towel then blast with a hairdryer to get em fully dry. lube and put them back in. might not be the best way to do it but its always worked for me. can also filter the degreaser and get a couple of uses out of it.
Citrus works in a pinch and I've certainly used it but a lot of the time it has detergents and other shit in it that leaves a residue, especially the cheap ones that you get from the dollar store. Personally I think the best way is using a good, strong, and relatively pure solvent (acetone, 91% isopropyl alcohol, fred gall's urine etc) that will evaporate quickly and cleanly for the cleaning step, then after its all shiny and new add the lightweight lubricant of your choice. I use 91% isopropyl or pure acetone depending on the situation since I have access to virtually unlimited quantities of both where I work. Acetone is really good but it will eat away at seals and even some retainers so I usually just use the alcohol to avoid having to pop the balls out and put them back together unless its a serious issue like them totally seizing up from rust.
For lube a lot of people love speedcream and it works fine for me, but I'm actually using this "liberty oil" stuff that was given to me by one of the grease monkeys where I work and it's pretty awesome. It's a really light pure synthetic oil that comes in bottle with the cheapest label I've ever seen, but it works wonders. I had a set of Flip HKD 7s that I got wet without realizing and they completely rusted, like the balls were basically welded to the races with rust and I had to break them off after taking the retainer out. After cleaning with alcohol for 24 hours and a little bit of elbow grease they were back to about the speed of a bearing off a kmart board. Added a few drops of the liberty and spun them a few times and you'd never know they'd been nearly destroyed other than the fact they're loud as shit now.