Can be used for metal-to-plastic and plastic-to-plastic contact and ensures you don't have any dry areas between friction surfaces and also ensures a good seal around washers and O-rings without causing them to soften or swell.
We find using a small amount of Abbey Silicone Grease around the neck of Co2 capsules can help improve the seal and protect the valve O-rings from drying out and becoming brittle which can lead to leaks.