We've just had a new Stoves range installed. Its electric (induction) with 3 ovens and a grill. I'm keen to keep it as clean as I (reasonably!) can and thought that silicone oven liners might hep, but I know that 2 of the ovens also heat from below. Is it safe to use these oven liners? I've read the instruction manual cover to cover but can't see any advice!