In article , Matt wrote:

[...] I know other homebrewers have used caustic soda
with great results so I guess I will give that a shot.

Try washing soda first -- it's a lot more caustic than baking soda, but not
nearly as dangerous as caustic soda (aka lye). If you do use caustic soda,
make sure to wear rubber gloves and eye protection.

Washing soda is available in many grocery stores on the same aisle as laundry
detergents. The most common brand is Arm & Hammer -- the box looks pretty much
like the familiar box of Arm & Hammer baking soda, except it's a lot bigger.