Our septic system consists of one 500 gal holding tank, and then spills over into a 500 gallon dosing tank.
Both tanks are pumped every fall, and then
https://www.amazon.com/Instant-Power-1868-Septic-Shock/dp/B08818GHMW/ref=sr_1_7?dchild=1&keywords=septic+shock&qid=1612379920&sr=8-7 is added to each tank.
This gives the leach fields a break, septic system is 24 years old, no issues.
I was a little concerned at first with the yeast being washed down the drain, but I think I'm ok.
Grain is thrown out with the trash. Live on edge of a national forest and have enough critters.
"Been a hoot-owl howling by my window now", 4 am this morning.
Regarding the yeast, it depends on size of tank, load on tank (people), and how often it's pumped.
A poorly maintained and/or highly stressed septic system is looking for a reason to fail.