If you fish for the rough fish a lot, have you tried giving them a rest for a couple of weeks and see if they "dumb" up?

I really think the way that you are going about it is about the best way possible other than getting an electrofishing boat in there.

Are 4"-6" golden shiners available locally? A different bait (live) might help.

www.hoosierpondpros.com

[Linked Image from lh6.ggpht.com]
http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).