Has anyone tried this stock tank water cleaner?

[KamiBrooks]

From the Jeffers Equine site:

"Bioverse, Inc.) A natural solution specially formulated to keep stock tanks clean & clear. Contains all natural beneficial bacteria to break down organic sludge. Each dispenser treats up to 500 gallons of water daily for 30 days"

http://www.jeffersequine.com/ssc/product.asp?CID=1&mscssid=3ENEJKP35WDJ9N8HVG2EMC7PV69FFG6C&pf_id=0027003&cmkw=B4-SC

I read about it in this Dec 2002 article and am thinking about trying, but wanted to ask if anyone else has tried, or is using bacteria/enzyme approach to trying to keep tanks cleaner?

http://www.dvmnews.com/dvm/article/articleDetail.jsp?id=41327

It would be nice to reduce tank cleaning.

[WarHorse]

I'd rather not add anything to the water they are drinking.

For me, I'll get in with overshoes on, a scrub brush and a hose. Tip the thing on its side for drainage.