I built a homemade version from PVC pipe and it works like a charm. It may take several weeks before they start to climb in, but usually once I catch one, I catch 8-10. As others have said, you cant catch them all but I usually thin mine down to two or three.
I rehome them in the large watershed area by my work.


1 acre pond, slopes to 15ft depth. Has BG and few LMB plus a half dozen pesky sliders.
[Linked Image from i108.photobucket.com]