While technically feasible with pure soap (which is lye fully reacted with food grade oil/fats), the stuff you find in stores will have stuff like:

• Conditioner
• Perfume
• Coloring

All of which are likely to cause irritation on your intestines and worsen the overall acid flux experience.

If you need to do this experiment for some reason, make sure you know exactly what is in it.

Fun fact: Old timey cheap industry soap (plain tallow and lye) used to be popular with rats and mice.