Having been 10 years in this RV both using and not using Chemicals I find that the Chemicals do one thing very well.. Flatten your bank account. Other than that they are useless for the most part.
Re: Dumping in house
Some of the chemicals will harm your septic system, Others may actually boost it (Biologicals, technically not chemicals) such as Rid-Ex.
The main concern I have is dumping.. My RV holds over 100 Gallons of waste divided into 3 tanks (Black/Gray/Wash) and that is a LOT to put into many home septic systems in one "Flush"