Share 'Any opinion on greasing the seal?'

I know with the casings you can buy for non-waerproof cameras you're supposed to wipe some grease along the rubber seal. It doesn't seem that this is part of the protocol for these waterproof point and shoots (e.g. the Pentax W60) but I'm wondering if it's worth doing. I assume it has to be the right kind of grease otherwise you might do more harm than good. Any opinions?