I did some more research using Gemini which is becoming a lot more accurate. They pointed out that other studies found that less than 20% might cause problems for a rodent but that none of the studies considered baking soda an effective rodentcide. The average amount of rodentcide to kill a mouse is around .2milligrams per kilogram and Gemini quoted approximately 21,000 times more pure baking soda would be needed. Now that is pure, not mixed 50/50 with bait food.
Who knows if those rats were killed by the baking soda or not? Apparently the baking soda doesn't react violently with stomach acid as the old wives tales claim and any gas build up goes right out the politician end of the rodent very easily. I have no doubt you found dead rats and thanks for mentioning it.
