Washed with TSP and Enzyme treatments.

That combined with a monthly enzyme treatment that I purchase at the local hardware store for about 8 bucks (about 60 applications) keeps the drains free and clear.  

Make sure exhaust smells nice while the dryer is runningEvery 1st day of Feb, May, August, November Put in the drain enzymes into all sinks per directions.

I like that it is enzyme based and cheap so I may give it a shot.  

There is an enzyme spray that I was introduced to about a year ago, I forget what it was called, but it took a house from smelling like a casino in Reno (tobacco smoke) to smelling like nothing in 48 hours it was mind blowing.

Over pumping can cause the enzymes that decompose sewage to become low level resulting in a tank that fills with solids quickly.

Yes, plants are harder to break down, thats why we were ingeniously designed the way we are.Cooking foods kills all the enzymes, and a chunk of the vitamins.

My dads property is on a septic and he's only drained it once in about 20 years but he puts enzymes down there and always buys the special TP.

I am strongly considering that.What do you think of those enzyme products meant to prevent buildup?

You have to hit it with an enzyme product like, I think it's called Pee Be Gone...or something like that.