Long drain line from kitchen sink - Best way to clean

The kitchen sink drain empties into a 2 1/2" PVC line in the basement ceiling. The 2 1/2" line runs 50 feet to a 4" PVC septic line that passes through the basement wall on its way to the septic tank. Due to the long distance between kitchen sink and 4" septic line, there is only a slight decline in the 50 foot 2 1/2" line. This means that deposits may gradually build up on the walls of the 2 1/2" line over time? After living in our house for 15 years, the line has never clogged. But I am trying to be proactive.

Is there a product that I can use to pour into the kitchen sink that will clean the walls of the 2 1/2" line and still be safe for my septic tank? Should I have it snaked periodically? Ignore it? Other comments?

If it's not plugged then there is nothing to be done other then keeping grease out of the line.

I've heard of a lot of people using baking soda and vinegar to clear drains and its not as harmful as drano and other harmful chemicals. The baking soda and vinegar create a natural reaction that should be safe for the drains. Also, snaking is helpful too but only if you know you have gunk or stuff lodged in there.

How to Unclog A Drain With Baking Soda and Vinegar

• Pour a pot of boiling hot water down your drain.
• Dump in about 1/2 c. baking soda. Let that sit for a few minutes.
• Then, pour a mixture of 1 c. vinegar and 1. c very hot water down on top of the baking soda.
• Cover with a drain plug (to keep the reaction down below the drain surface) if you have one and let it sit for 5-10 minutes.
• Flush one more time with a pot of boiling water.