And before you even try to remove the screws from the diff, heat the diff up with a heatgun or throw them in the oven for a little bit to weaken the loctite that is on the diffs. If you don't do this, it will be much more difficult to take apart the diffs.

For cleaning out diffs, I personally like to use mineral spirits. You can get this at any home depot or hardware store. The reason I like using mineral spirits over carb cleaner is the exact reason that Blitz had mentioned earlier, some carb cleaners are so strong that they may eat the plastics. The routine I have for the diffs is like this, I clean out one diff at a time, this way I don't have to worry about resetting the gear mesh between my ring and pinion gears. I generally just take the diff case off and pull out the six gears. Then I just put the gears into a little container of mineral spirits and get a toothbrush and start scrubbing away the old grease or oil.

For the Nemesis I do like running the setup Blitz mentioned, 10/30/5. Also while you have diffs out check the bearings on the outdrives. When you have the diffs apart, check the bearings to make sure they are not getting rough or notchy. If they are, replace as needed.