Purple degreaser from Lowes or Home Depot was my favorite. Put the glass in a plastic bucket and cover with pure purple. Do not dilute. In a day, the glass should be clean enough to wipe with a scotch brite and rinse. I always bead blasted the spinners lightly before repainting them. Don't use a lot of pressure as the glass beads an heat and warp the metal. Do not use Purple on those pieces as it might eat the metal away? Paul