Thank you for your comments.
I read somewhere that pork rinds would be working and they hold up well on the hook. I will definitely try it if mackerel is lacking. I checked here at the supermarket and a 1kg frozen mackerel sells for about 8 dollars...as for smelt, not being "fat" enough, striped bass would not be attracted but I will probably try it. Anyway, if it doesn't work, I'll eat them!