Pressure cooker gaskets

You hear recommendation of one time use of vegetable oil or petroleum jelly on a new pressure cooker gasket.  Neither work real well and seem to make gasket swell and cause further deterioration.  Course many now recommend replacing the gasket every year or two "for safety".   Nice scam to make a cooker that needs a new $20 gasket every year.

I am excluding modern silicon gaskets as I have little experience.  But for the older rubber gaskets, many of older pressure cookers came with a red rubber gasket that lasted decades until they finally dried out and got brittle.  Modern replacements obviously made of a different material, and usually colored black or white, though see some grey ones.

My guess, those old red ones were made of a natural rubber and newer ones some type synthetic rubber. 

Anyway I have been experimenting with silicone grease.  Also called plumbers' grease, food safe used in faucets, industrial food processing equipment, etc.  So far this seems more effective at least on the white gasket I am currently using.  Time will tell.  They do say not to use this on silicone gaskets.  It does require occasional reapplication.  More often if you remove the gasket after every use to wash it. 

I did notice you can buy a 12in by 12in square of natural gummy rubber, 1/8in thick.  Around $15.  I would sometime like to try homemade gasket cut from this.  Course one has to take the sellers word of what it is.  Of course this would only work with older cookers that use a flat gasket.  Modern ones tend to be C-shape or other hard to replicate profiles.