I quit using RV holding tank chemicals a long time ago. If it works in a washing machine, it's safe for my Septic Tank and any place else, especially since my washing machine flows into my septic tank! Bleach, water softener, laundry soaps of all brands, ... if it's washing machine safe, it's septic tank safe! Same with toilet paper.
A couple years ago we had an easy access clean-out installed on our septic tank. This opened the opportunity to get a bit creative. I do wish the pipe would have come closer to the ground, and I didn't want to run the risk of cutting it, possibly splitting it, or ruining it, so decided to come up with an alternative. I built a ramp. Unfortunately, my TT is in the drive way, and the septic tank is at the back of the house. But no problem at all. This works GREAT! And ... have had no issues with dumping into my tank at all from the camper!
The good thing is, this ramp is just temporary, can be removed at will at any time.
But, back to the OP's post. We used the Port-a-potty in the camper at home for years so we can winter drive way camp and not have water in the system. Unlike the plumbing in an RV, a port-a-potty does not have vents and such, so we used RV chemicals in the port-a-potty for years to keep the smells down. And then I'd dump into the toilet at home. It seemed to never affect the functionality of the septic tank.