Cooking liners - anyone used?

[Oldisthenewblack]

I bought one of those 'cooking liners' yesterday, and used it today for the first time. It stated on the packaging that it "keeps trays and pans clean" - and after use to wipe (the liner) with a damp cloth or wash in soapy water. Was a bit surprised to find that there was a layer of grease on the baking tray after use, so the tray still needed to be washed properly, and even after washing the liner (which is reusable) thoroughly, it still smelt greasy.

Has anyone else used these, and does the greasy smell linger after washing? I only wish I had more interesting things to occupy my mind