Here are the chemical names (hyphens added for comprehension) for what MarshWallow contains:

And here are the shorter CTFA names:

All of these are surface active agents (surfactants) -- soaplike substances for making foam. They're made from tropical plant oils.

Also in there:

No additional water was added during manufacturing, so MarshWallow is quite concentrated compared to most. The maximum amount of sulfite which may be present could cause a reaction if a sulfite- sensitive child were to drink a substantial amount directly from the bottle, but is not a hazard in bath water or in bathroom air. MarshWallow's pH is close to that of skin.

This product contains no SLS and no DEA. Although I don't believe either of those ingredients to be major health hazards, I left them out because they tend to irritate, waterlog skin, sting eyes, and feel sticky and difficult to rinse. MarshWallow contains no fragrance, coloring, preservatives, or alcohol.

Is MarshWallow "Natural"?

I honestly don't know the answer to that question, because people use the word in so many different ways. Do the ingredients look un-"natural"? For comparison, here are major constituents of a typical piece of homemade soap, expressed by their chemical names:

and their CTFA names:

Some makers would try to make their products appear more "natural" by loading up with ingredients having familiar household, botanical, or otherwise non-technical names first, so the technical-sounding things which do the real work of the product would appear last on the label. MarshWallow doesn't play that game.