I always wondered that as well, my old TA02 never even provided any of this AW Grease stuff.
After reading this I went and cleaned out all the AW Grease out of my car. I found it abit weird that in the manual (unless I missed that part) it only said to apply the grease on the wheel side and not on the diff side.
It's all cleaned out now so all is well. The way I did it was pull everything apart, get rid of as much as you can with paper towel, it should take away most of it. To get the residue out of the cup thingys, I used a Q tip. Then I just took all the parts put it into a bowl of warm water, added some dishwashing detergent and scrubbed it with an oil toothbrush. Rinse and dry with paper towel. Came out sparkling.