Toilets, Sinks, Showers, Tubs and Disposals - Vinegar & soda to clear drain

I have a farily long horizontal pipe from the shower to the main vertical drain pipe (12 ft). The drain slows regularly (2-3 months) when soap scum builds up in the drain pipe. I keep hair out with a screen. The vinegar and soda method seems effective on some of the blockage but I can't get it to the more remote part of the pipe because it reacts in the earlier part of the pipe. The enzyme I have tried didn't do much. I have tried putting the soda down the tub drain and the vinegar down the shower drain but didn't get much reaction.
Any suggestions?

A plumber friend recommended pouring boiling water down the drain occasionally to help keep the pipes clear.

If the line from the shower drain to the main stack is accessible, open up the clean out and scrape it out. Once it's clean make sure the pipe is pitched correctly. It shouldn't clog the way you describe if it has the correct slope.

Personally...I have done the vinegar and soda thing and it looks very impressive, with it's fizzing. But actually, I think it is almost all show. The best means is mechanical cleanout with a snake. But if you have a drum trap you are screwed (if it is buried/covered up), as a snake will not go through one of these. I have seen drum traps where there never were any good provisions to get to the coverplate. Some are accessible like behind a panel in the wall on the other side of the shower or tub. Then you have to remove the cover, which can be tough iif it was never removed before or in recent history.

*I* did this once and am not endorsing this and you do it at your own risk: I used an acid drain cleaning product that is I believe, sulphuric acid for drains (it has skull and crossbones on it and is wrapped in plastic and only sold in plumbing stores), not in my local Menards as they only sell (hydrocloric acid for toilets), and poured THAT down the drain and let it sit for a while. After THAT did not clear the drain, unbelievably to my surprise, as heat was coming out of the pipe!..I added baking soda/ water down the drain and I stood back. I knew there would be a violent reaction, and there was. I put something very quickly over the tub drain. I heard all kinds of booming and banging going on in the pipes for the severe reaction between such extremes in ph...but it cleared the drain. What YOU did with the vinegar and soda is the same as what I did, in essence, but because my acid was so much stonger than vinegar's acid, the reaction becomes that much more severe, and the expansion of gases in the pipe, beyond puny fizzing like vinegar, is what caused it to blast it's way through the clog. If ever you get splashed with the acid/reaction you must be prepared in advance to get it off of you quickly/dilute it, with water, and maybe some soda mixed in.


But do try snaking it first and I hope yor house is newer and/or remodeled bathroom where you have no (buried) drum trap.