Kick Sticks for Swimmers: Do They Really Improve Performance?

Question
Dear Sir:  Have you heard about the Kick Sticks a biomechanical training device for swimmers designed to enhance performance, by limiting the upward flexural motion of the leg during the flutter kick as used in the crawl or backstroke. Do these really help you swim faster?  If you havent seen them check out www.bothhands.com
Sincerely Kirk

Answer
Marlin-
Prior to visiting the website, I hadn't heard of the Kick Sticks.  After reading about them, It is possible that they can be beneficial, but are they cost prohibitive(I didn't go that far into the site)?  If so there are drills to improve the same muscles as these train.  If interested in some drills let me know.  If the Kick Sticks aren't too expensive-give them a try and let me know how they work.  Best of luck.
George