Has anyone ever used a repeating crayfish trap from terrybullard.com?

Looks like crayfish are better than worms - you can catch alot of fish - and crayfish are pretty hardy too. Those crayfish are pretty hard to catch by hand though. Just would like to know if anyone bought one of these repeating crayfish traps from terrybullard.com, and love to hear your story on how they worked for you.