Need some for frem diaries and was wondering if they're rare and whether a ROW would help get them?

u don't need chewed bone u can just rummaging the barbarian skeleton to get the another bone called Mangled bones

this work as well in task

 

(Row don't help the drop rate of chewed bone)

Not very and no.

you can get one within 10 ish kills easily.

Theres a barbarian spirit on the ground floor that 100% drops mangled bones.

And you can do the task with these jsut the same as chewed bones.

Thanks for the quick answers guys