Since I have a tire changer in my barn, I have changed some tires that had Slime in them. It does make an awful mess, and every steel rim that I've changed that had Slime in did have a bit of corrosion present inside the wheel. Other than being an awful mess to change, the corrsion was not nearly as bad as some rims that had gotten water in them. Maybe 10 to 15 years down the road there may be an issue, but it would take a while. If you take a tire with Slime in it to a tire shop, they likely will charge you more for a tire change because of the mess it makes though. Like most things, it's a trade off.