Local janitorial supply store - 55 gal drum of 12% for $150

[JohnT]

MSDS says:
*Sodium chloride - > 50%
*Sodium carbonate - >30%
*Sodium percarbonate - >10%

What you've found is basically a generic version of Oxi-Clean:

Sodium Chloride is salt
Sodium Carbonate is soda ash or pH Up
Sodium Percarbonate is the active ingredient in Oxi-Clean