Doug Miller wrote:

Why not just buy hydrogen peroxide and washing soda, and mix them?

Sure. The result would be the same.


They're both readily available, cheap as dirt, and bound to be less expensive

When you say hydrogen peroxide is "readily available" and "cheap as
dirt" I of course think of those brown plastic 16oz bottles they sell
everywhere, from WalMart to Walgreens. There are two problems:

1) That's only a 3% solution. You would have to use it full strength.
So, not sure it would much cheaper, if at all.

2) The reason it's in a brown plastic bottle is that it's unstable.
Has a short shelf life. The powdered sodium percarbonate keeps much
longer, as long as you keep the lid on it to keep the moisture out.


You can buy much stronger hydrogen peroxide at some pool and spa supply
stores, but it's expensive - and at high concentrations is somewhat
dangerous to handle.



and easier to find than sodium percarbonate.

Sodium percarbonate is easy to find. It's the active ingredient in
OxyClean and other oxygen-based cleaners which line the supermarket
shelves (but as I said, those products contain a lot of filler - they
are not 100% sodium percarbonate). Most pool and spa stores carry
"oxygen shock" which is sodium percarbonate. Many mail-order places
sell it. Type the words "oxygen" and "deck" and "bleach" into your
internet search engine, and you'll get hundreds of hits.


If you only "used to" be able to buy washing soda in the laundry aisle, either
you're shopping in the wrong stores (e.g. Wal-Mart), or you're not looking
very hard. I don't have any trouble at all finding washing soda in the laundry
aisle of my neighborhood Kroger grocery store.

WalMart and Meijer used to carry it in their laundry products aisle but
they no longer do. I also checked two or three other chain stores and
they don't carry it either. Haven't checked Kroger yet - but I will.
While I'm there, I'll also look for "20 mule team Borax" which WalMart
also stopped stocking (I've had good results using a Borax and vinegar
solution for spraying on treated pine and vinyl siding to
prevent/destroy mildew and algae).


Speaking of WalMart, is it just my wild imagination, or do I sense a
slight change in their business model? Besides Arm and Hammer Washing
Soda and 20 Mule Team Borax, there are other low-volume products I have
seen disappear from their shelves recently. In the past, I had the
impression they wanted to be all things to all people. Now lately I
seem to perceive a trend to eliminate some of the low-volume stuff.
They may save a nickel in the near term, but people may start to
re-discover other stores. That may be a good thing.