Removing grease stains from dark wallpaper

[RockingMyFiftiesNot]

We love the dark wallpaper in our dining room. It was expensive, is still perfect 20+ years later but has some grease spots in a couple of places. Any thoughts on if/how these spots can be removed or at least improved? I've just assumed we'd have to live with them but nothing to lose by asking! Thanks

Give it a rub with a slice of white bread

Thank you @CeeceeBloomingdale - I had heard that tip before come to think of it. No white bread at the mo but will get some and give it a go