Rosewood make a product which is just dandelion root and nettle root, and while it isn't something that should be chewed in excess they can make a really good non wood chew for hamsters who just aren't bothered with wood.
https://barksandbunnies.co.uk/produc...n-nettle-roots
Those happen to be one of the decent quality Rosewood treat products. You can find them in a variety of stores that stock Rosewood items - but these particular "treats" I would consider a valuable tool in the arsenal of a hamster owner as they are sometimes one of the few things some individuals will even bother chewing on.