Observed this lunacy the other day... so apparently, this is how you do it right:
1. Turn on machine.
2. Clean the legs, with windex and a dirty rag. Make sure you spray liberally getting windex all over the cabinet in the process.
3. Pull the glass.
4. Pull the lockdown bar. Clean it with windex/dirty rag.
5. Move your four foot tool cart between you and the peoples so they can't see what you're doing. Maybe.
6. Pull out your denatured alcohol, magic eraser.
7. Start to remove random plastics from the game, while attempting to look like you know what you're doing.
8. Spray windex on the ramps (with the game still on, very important), playfield, and anywhere else you think it might need it. Make sure you use way too much, you wouldn't want to accidentally leave any wax in place the last guy might've put on there, or not make sure the inside of the light sockets don't get cleaned!
9. Scrub playfield with magic eraser.
10. Wipe down with dirty rag, casually cleaning up your overspray onto the inside part of the cabinet.
11. Walk around for 5-10 minutes.
12. Clean legs again.
13. Clean lockdown bar again.
14. Replace glass and lockdown bar.
15. Clean top of glass, since that's the only part now exposed, and the lockdown bar again.
16. Clean legs.
17. Give it a play test to make sure that nothing is on fire.
18. You're done! Go talk to the other employees, who find you wierd anyways because you "know how to work on a pinball machine."
Make sure that at NO POINT during this process, you make any attempt to adjust any malfunctioning switch, work on the flipper mechs, replace broken rubbers, fix dirty optos that don't allow people to lock the balls, or clean the DMD plastic which looks like smoked plexi.