dave1812: "hydrogen peroxide ... Dry Oxi Clean contains sodium percarbonate and sodium carbonate. How does that differ in action, from the liquid version? ... different active ingredients..."

I suggest you read up on sodium percarbonate (see, e.g., the article linked below) which probably will answer all of your questions. You will find that -- essentially -- sodium percarbonate is anhydrous (dry) hydrogen peroxide; it is, in fact an intermediate chemical in the commercial production of hydrogen peroxide.

The liquid hydrogen peroxide you can buy in brown bottles at the drug store usually is a 3% solution of H2O2 (hydrogen peroxide); that is, the liquid is 97% water by weight. The bottles that liquid H2O2 is sold in are brown because, exposed to sunlight, H2O2 breaks down to water and oxygen gas. The "extra" oxygen atom in a molecule of H2O2 is what oxidizes (bleaches) clothing or teeth or disinfects wounds.

Most of the contents of a package of Clorox2 or Oxi-Clean comprises fillers. You can purchase nearly pure sodium percarbonate from chemical supply houses for a much lower cost per unit of active ingredient -- the same active ingredient of the filler-burdened Clorox2 and Oxi-Clean -- than you will pay for an equivalent dose of Clorox2 or OxiClean.

The Ecover brand of oxygen bleach is "pure" sodium percarbonate; I put "pure" in quotation marks because exposure to the air inevitably and quickly starts a chemical reaction to reduce purity to about 95%. "Pure" sodium percarbonate such as Ecover or the chemicals that you can buy in bulk is strongly hygroscopic: that is, it absorbs water from the air. If your laundry room is damp, you should store any sodium percarbonate product in a sealed plastic container that you open only to dispense it to your laundry, and then close again.

Here is a link that might be useful: Wikipedia article on sodium percarbonate

great info! thanks so much. didn't realize that sodium percarbonate is hydrogen peroxide in another form. my wife wants us to reduce the number of chemicals we have sitting by the washer/dryer. LOL! she wants simplicity. :)