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

Best stuff to clear black tank censors

My Black Water tank sensor was not reading. I put this product in the empty tank, and filled 3/4 full with water. Within two hours, sensor started reading, looks to be accurate. Going to drive and let the cleaner slosh around anyway, but seems to do what it says--clean the sensors!

Have used this product several times as directed and it seems to help clear the black tank, but not completely. It could be a bad or stuck sensor that will not clear.

Our sensors haven't showed an empty black tank for well over a year. Added this to my black tank and filled the tank with water. Let sit for a couple if days and left in until we arrived at our next campsite. Once we arrived at our site, I drained and well flushed the black tank. Checked the tank level again, and was pleasantly surprised to see it show an empty tank! 😃

Works great, both in pouches and liquid. A fraction of the price of the other brand I was using, and works just as well on my boat holding tank.

This didnt help any faster then the regular flush out with water trick until water is clear. To me, both worth the extra money, but it smells nice.

First time using these. My Roo is a 2013 and I don't think the previous owners ever actually cleaned the black tank. It was FOUL. It took two treatments, but this stuff kicked it. Definitely recommend filling the blank tank FULL and letting this stuff percolate as long as you can, but at least 24 hours.

This is the Best ! Works Great !

Good product, does exactly what it says on the tin

is what it means

Despite using tank cleaning drop-ins regularly and using the tank flush, we would consistently a 1/3 full reading immediately after emptying. We dropped one of these into the tank, filled per instructions and let the solution sit for approximately 12 hours. Emptied and tank flushed again and after a moment or two, the tank indicated as empty so it worked perfectly! The only think I wish is that these RV necessities would be less costly - on a cost per use basis, we are paying just over $4 per drop-in (after tax). True, you shouldn't need to use them very often but that's still a lot. They do work though, so I guess my mindset should be that you get what you pay for.

良い

Product does not clear tank sensors but great deodorizer Reviewed in Canada on July 15, 2026 Scent: Lavender Size: 502.8 ml (Pack of 1) Smells great but does not do the job as advertised. Followed directions appropriately- filled black AND grey tanks to attempt to clear both- drove 50k with product and water in tanks then left it for 4 days before emptying- absolutely no change in tank readings.