Found an interesting bit of info on this website:
http://www.attapulgite.org/
The structure is somewhat between laminated and chain structure. Attapulgite looks like soil, and compact blocks which are found in the sedimentary rocks and the weathering crust. Attapulgite are white, hoar, caesious or celadon, or with some dim mercerization in color. The clay of attapulgite is fine and a bit greasy smooth, light in weight, crispy, and the fractured surface is like shells or in irregular shapes. Attapulgite has strong ability to absorb water. When it is wet, attapulgite shows plastic and adhesive properties; and when it gets dry,attapulgite does not shrink much and does not show cracks. When it is soaked in water,attapulgite collapses. The suspending liquid does not create soliquids and precipitates, when meeting electrolytes.
(My underlining)
So, I have a few questions:
Has anyone used this stuff personally?
Do they find it suitable and
Does it break down - if so, how long do you think it lasts?