Cowbelle, Those selectors IMHO will need solvent. Get some stick on panty liners or some cosmetic pads and pack the edges and bottom - get a depend and cover the base of the machine - you don't want solvent on your paint. Then paint some solvent on the selectors - you don't have to remove the cam stack - it is a little easier to clean the stacks though - The Tri-flow might penetrate that screw if you turn the machine upside down - heat may help. I've taken the whole selector mess apart before to clean it - kind of hard to get it back together unless you have a really good memory and like to do puzzles. Some solvents are made to evaporate quicker than others. When I use a solvent, I drink a LOT of water and I try to take a detox bath afterwards - I have a lot of chemical sensitivities so I try to do it out doors on a windy day, too. There are some dried up oils that do not come off very easily. You may need something that will more or less vaporize that gunk.