I was looking up some Ojibwa recipes, and ran across this collection from many tribes: lots of substitutions there. Wheat, sheep fat, baking powder... just like the Italians took to tomatoes. (Norwegians say they don't eat lutefisk anymore--they have refrigerators now. Only in Wisconsin...)
Several Navajo recipes used juniper ash. The ash was mixed with water and then strained out to provide an alkali to mix with the corn. Corn needs a little tweaking to get full nutrition out of it. Cooking is enough for most foods, but corn needs a little "nixtamalization" to make the niacin available. (I gather that there were epidemics of pellagra when corn became a staple in Italy. Italian cuisine didn't include the extra tweaks needed.)
One side effect of the processing with alkali is that the corn hull softens, and another is that you can mash the corn up to make a dough. Those effects would probably be the goals for using alkali water--it isn't something I'd think of adding just for the heck of it. And the extra nutrition comes along as an extra benefit. But who knows--the developers of corn didn't leave any records and they might have indulged in systematic nutritional studies on mice the way we do. Which ones get fatter?