1. I started by scrubbing them with a dry toothbrush to loosen caked-on dust. Then I used my vacuum attachment to remove all the loose dust. Finally, I wiped them with a damp paper towel to pick up the remnants.
2. No need to prime when spraying plastic. Just follow the instructions on the can and start spraying. If you’re painting something as ornate as this, you’ll have to spray from every conceivable angle. Then, just when you think you got every spot, you’ll find another you missed. It took me a few coats to make sure I covered the entire surface. Let dry for at least an hour before moving them and at least overnight before using them.