Need some advice from the experts.

I've got some Zaino and Griot's stuff in my garage, and some of it has been in there for over 5 years at this point. Would you use it, or start fresh? If you start fresh, how long would you keep the bottle of whatever-it-is before replacing it?

There is lots of stuff. Car wash, Zaino wax and polish, convertible fabric protector, leather cleaner and protector, and more.

Thanks in advance.

 

I stop using it if it starts separating or loses it's effectiveness.

 

I agree with quality_sound. If the color is off, or it has separated, and with a good shake does not go back to the original look, time to get a new batch.