Sodium percarbonate

Sodium Percarbonate is the most expensive of the ingredients found in the powered cleaners homebrewers use. It also cleans very well, and is an approved sanitizer when used alone. It breaks down into Hydrogen Peroxide and Sodium Carbonate. Temperatures above 110 F help it dissolve faster. My chemical sales rep says this is what most of the wineries in the region use as their cleaner.
Hazmat fees apply to amounts over 2 lbs

http://www.chemistrystore.com/sodium_percarbonate.htm 2lb / $4.00
http://www.chemistrystore.com/Sodium_Percarbonate_Uses.htm