Nova I've had very good luck with Formula 409. It's not 100% safe though. On some inks, especially cardboard cans, it might lighten them. It's only lightened the paint on one metal can I used it on. Squirt a bit on a paper towel and dab a bit on each different area. Be sure to wipe it off quick and check the paint on the can and look for the color on the towel too. Then apply again and wait a bit longer. Sometimes the paint damage takes a few seconds. Don't let a quick test make you think you're safe and cause you to go full bore only to ruin the can.
Also another pretty safe thicker grease remover is the orange based hand cleaner Harbor Freight sells called Goop. I tried it on a whim years back on a Fox Head 2 gallon oil can so covered in grease you couldn't see the red letters or the fox! That can looked almost new when completed. Same testing rules apply though.
I'd say 1 outta 15 maybe 20 cans I clean have paint loss of any type. When I'm done I usually 'deactivate' the cleaner residue with a moist paper towel wipe down.
Last edited by tmcnasty; Thu Jun 22 2017 09:48 PM.