Do rattle bobbers really help catch crappie, or scare them away?

[Barnacle Bill]

I have had times when noise attracts them and other times they spook them. That is especially true with white perch.

[hdhntr]

Yeah, something like that. I don't know as the rattle bobbers attract fish, but likely don't repel them ... unless they're already very spooky. But, one thing they are good for is extra distance on a cast.

you had me with extra distance on the cast!