Walex Commando RV Black Holding Tank & Sensor Cleaner - Eliminates Waste & Paper Buildup, Restores Sensor Function, Lubricates Valves & Seals, Advanced Enzyme Formula; Dissolvable Packets, 4 Count

We had a tank sensor stuck on full. Used these and filled the tank. Drove around a little and drained the tank. God as New these work fantastic Highly recommend them

So we bought a travel trailer third-hand. We believe the black water tank was emptied before it sat up for the past year, but not cleaned out in any way. So we've been having to force down waste for a couple weeks. I searched online for a solution because the regular black water tank treatments meant to dissolve current waste and toilet paper weren't helping at all. I used a method described by others online, putting hot water with dishwashing liquid into the tank. I even added baking soda for some softening and slip. That caused a rush of gunk to flow out and resulted in a really awful stench (I guess it got some of that old stuff moving!), but still stuff was clogging near the top. Maybe doing it again would have helped more, but I went ahead and bought this product after reading the good reviews.Well, we emptied the tank again (or so we thought) before replacing the toilet. After removing the old toilet, we realized the tank was clogged again and the waste was almost to the top. I opened a Commando packet and poured it right in. I cleaned up where the old toilet sat, my husband installed the new one, and I checked the sewage level with every flush expecting that at some point it would go down.About 6 hours later, I noted that the level had gone down some. It was still pretty high up, but that was progress, and I knew it would take longer. Well, I just checked again. It's been 20 hours since I poured the packet in and I was shocked to find that not only is the waste too far down for me to see it anymore, but I can see sunlight coming in through the tank walls. I don't see one bit of gunk stuck on it either and the stench is gone. My gosh, this stuff really works, and it only took one application. Keep in mind that we throw away most of the toilet paper (all from #1 but not #2), so it's not overburdened with toilet paper--at least not from us.Expecting more of an issue, I actually bought the bucket of 40 packets and I was expecting to use one a week. I'll see how it goes, but I may not actually need this many after all. I do not regret the purchase at all though.

We 've been motothoming for 30 years and a constant frust ration is holding tank sensors.Our current coach has sensors on the outside so they are not supposed to get clogged. B S!The black tank has never shown a correct reading with a few exceptions.We tried this product using one pack per use and followed the instructions as best we could. It certainly works to control odors as well as any but we saw little if any changes in sensor accuracy. Not a bad product but no miracle cure.

This stuff straight up works! I filled my black tank with water a few weeks back, dropped one of these in, took it to storage about 2 miles from home. Today I picked the RV up and brought it home and dumped the black tank. Voila it reads empty. Wow, this is the first time in the 4 years that I’ve owned it the black tank monitor is reading empty.

We have a 2022 Sunseeker motorhome and the black tank sensor always showed at 3/4 full even after dumping. I put the tablet in the tank and completely filled the tank with water. Left it in for a week and then drove 120 miles before dumping. Sensor shows correctly now. Would definitely recommend!

I used these for 6 months while living full-time in my RV. I recently noticed a slight odor when flushing. I flushed the tank and doubled the recommended quantity, without relief. In a small space, odors can be a huge problem. I switched to another brand and the odor is gone.

this product has kept my RV holding tank clean during an 8,000 mile trip over 2 months.

I dropped these in my filled black tank because my sensors were not working . I waited 2 days emptied the tank checked the sensor readout and yes the sensors were working again.