Finches

Hi mseed. I think you must be taking about a niger seed feeder that has tiny feeding holes. I personally have never had much joy with them but I know some people have.
We have goldfinches, greenfinches, bullfinches and chaffinches come to our garden and they all love sunflower hearts. I once had niger seed feeders out as well as sunflower hearts and the niger seeds were ignored. 
Good luck.