ComStar Pure Lye | 99% Pure Sodium Hydroxide Beads | Eco-Friendly, Industrial Strength, Biodegradable Drain Opener | Safe on Fixtures | Static-Free, Unique Beads for Soap Making | 1 lb. (30-500)

This stuff really works! I had a really bad clog in my kitchen sink and I'm on septic and since this is safe for septic tanks (except MA due to state law) I figured I'd give this a go before asking my SO to snake the drain since that's such a messy job. I ended up using the whole bottle to clear the drain. The clog was so bad that it literally took ~6-8 hours to drain the sink. The bottle comes with ~2 cups of beads. You use 1 cup per application so if you only have to use 1 cup to clear, you'll have enough left over for a future clog. See below for exact steps I took.The first cup, I followed the directions almost exactly: waited for the sink to be empty, poured 1 cup of beads down the drain, boiled ~3 cups of water and poured all of it down to dissolve the beads, heard a growling sound for a few secs, waited ~5 minutes then ran hot tap water to see if the drain was clear... it wasn't and didn't seem to make a difference at all.So I did a little research on the net and found that you should let the pipes empty as much as you can down to the clog or the lye can become too diluted by the time it reaches whatever is causing the clog. So with the second attempt, I didn't use the kitchen sink all evening and let the pipes fully empty overnight. Then first thing in the morning I poured the rest of the bottle down the drain, boiled water again but this time I only used ~1/2 cup to dissolve the beads. I poured just enough water until the beads were dissolved and the "growling" sound started. The sound went on for a bit longer than the first time I used it and it seemed to "fall" away from me as it went down the pipe. I then left it for ~2 hours. I then boiled ~3 cups of water and poured it down the drain. Again, I heard the growling sound and assumed it was still working on the clog so I left it for ~15 minutes. Again, I boiled ~3 cups of water, poured, growling sound, left alone for ~15 mins. I repeated this process (boil ~3 cups, pour, left alone ~15 mins) until the growling sound stopped (maybe 4 or 5 times). I then ran hot tap water and it looked like it worked but then both sinks filled slightly above the drain. I turned off the tap and about 20 secs later, the drains bubbled a bit then emptied as expected. I then ran hot tap water for ~3 mins and no more clog. The sink drains like a champ now! I will be ordering more of this stuff so I have some on hand for the next clog. Highly recommend.

tl;dr: Had slow draining tub. Tried everything. Nothing worked. Did Pure Lye + 3 pots of boiled water. Problem solved.I don't write too many reviews, but this product is more than worth the $$.I have been struggling with a slow draining bathtub for about a month.Every time I took a shower, the water quickly reached ankle deep. When my wife took a shower, the tub was half full.Of course the result is that lots of hairs and dirt remains in the tub after the waster drains in a few hours. Not very sanitary.During that time I tried every clog remover method available to men.Draino MAX? Tried it. Hot water? Many times. Plunger? 'Till my arms hurt. Baking soda and vinegar? Had no effect. Snake? Nothing came out.I requested a maintenance service to the management, but they simply ignored it.So after searching around the web, I decided to purchase Pure Lye Drain Opener as a last resort.After waiting for a week, it was finally delivered today. As soon as I got home, I went to work.I boiled a pot of water and poured it down the drain. While the water was slowly going down the pipe, I poured 1/4 of pure lye into the drain opening.I didn't know what I was hoping for, but the reaction was bit of a let down. The beads didn't look like they were dissolving and water was still draining slowly. It actually looked like water was draining even slower!So I poured more Pure Lye into the drain and boiled another pot of water.When I poured boiled water in the drain, there was a distinct reaction as I saw the beads dissolving and flowing into the drain.I turned on the faucet and as the water was draining (still a bit slow), I heard gurgling sound within the pipes.I poured even more Pure Lye and another pot of boiled water into the drain. It was looking very good indeed!After about 3 hrs, I decided to check out the drain as I took a shower. Lo and behold! The water was going down like it's never been clogged! What a relief!I had used about 2/3 of the bottle for all this work. I think I'll use the remainder at the first sign of trouble.This will be the only clog remover/drain opener I (or anyone) will ever need.