Those are two ideas i had to reduce griefing.
The glasses would be made with glass and some kind of newcomen processed steel and would allow players to spot small items (like seeds, needles, or those tiny mechanical parts) and items behind trees more easily, by giving them a broad white outline that shines through other objects.
If possible they’d not count as a hat, but would have their own category (maybe accessory).
The butter knife would be add another step when using the steel file on a blank steel blade.
Blank steel blade > Blunt knife blade > Knife blade > Saw blade
It could be used for everything you currently need a knife for, but isn’t commonly used for griefing, like cutting and buttering bread, slicing cake etc., while the real knife could be safely guarded by the person who cares for the animals or by people who go on hunting trips.