Does not leave a slippery finish. This should be used carefully and very infrequently. It will clean just about anything out of vinyl. A great cleaner for vinyl tops. I don't recommend use on the inside.
Some people do and swear by it.
Sonax Cockpit Spray - This is a German product that is designed for German vinyl. Does a great job, but leaves a little more shine to the surface than I care for. There are a gaggle of users who love it. Wurth Cockpit Spray - ditto above. Wurth people don't like Sonax and vice versa.