Pete Keillor fired this volley in
:

The caustic concentration must be very low in those products.

They are, indeed, Pete. But "lye" is what it is. It's usually potash
lye, not soda lye, but either will work. The reason is the resultant
sodium salts are hygroscopic and can cause corrosion after the cleaning.
Proper rinsing can prevent that, but it has to be thorough. Thus, in
industrial settings, the sodium version is less expensive, and
satisfactory. For "field work", the potassium version is preferrable.


Lloyd