Aqua Sinka is a New Zealand company that produces non toxic, lead free fishing sinkers.
They offer two different fishing sinkers, Sinka and Soaka. These products are made from naturally occuring ironsand and if lost during use they will eventually return as natural, safe components to the environment. Soaka has the added feature of acting like a burley bomb. The Soaka sinker absorbs approx 20% of its volume in the specially formulated SOAK-IT fish attractant. The slow-release attractants seep from the Soaka sinker while it sits near to where you want it to be, your baited hook!
The Aqua Sinka products are available from their shop at the following website: http://www.aquasinka.com/