CR 250 MXer,
Harsh solvents like brake cleaner can in fact cause rings to dry or swell.
Usually only if left on for long periods of time though.
No matter what you use to clean your chain, if you lubricate it immediately after, your rings will probably survive.
Problems occur when you clean with a solvent and do nothing else. A dry ring can eventually crack (similar to dry-rot). It also will have a tendency to want to relubricate itself and it will use the oil that it was desinged to keep in place if you are not oiling it yourself.
Kerosene is a great solvent to use, just remember that you need to lubricate after.