Use the alchohol and a tothbrush to throroughly scrub out everything. I would not use WD40, but if there is caked on goo from afterrun oil and/or nitro fuel that has dried up in there, I guess WD40 can be used to help penetrate that gunk. Then, use the alchohol to clean throroughly. Before reassembling, lightly coat the parts with afterrun oil.