In my own experience, clogs happen as you’re flushing, with the dirty water coming up and threatening to overflow. If there was a way to stick this on in less than 1 second, with it making a positive seal even if the rim is dirty, then great, as it prevents a mess AND gives you a way to bust the clog.
But otherwise, I’ll stick to using a plunger (which should be standard equipment, anyway.
Where’s a Dalek when you need one?
There would be instances when this would not work quickly enough, but most of the time it would, and be a lot more hygienic than a plunger.
But what do you do with it afterward? You don’t want the underside spraying dirty water everywhere as you unstick the adhesive, and would you really want a used one of those sitting in the trash bin?
Holy crap! If that thing broke you’d be in deep shit.
Quite possibly literally so as well 
It appears as if the pressure is pushing dirty water back up into the tank. This could lead to contamination of the fresh water supply, which is a serious issue. There’s a reason there is an air-gap between the tank and the bowl on a toilet.
This is a pretty nifty solution, though the failure mode is a lot more catastrophic than a plunger.
The tank water is separated from the rest of the house by the tank valve as well as the air gap between tank and bowl. The only way you’d get contamination into rest of your water supply would be for the fill valve to become submerged and stay open. Which shouldn’t ever happen, right?
Nah, I don’t see it as a risk. Clean water systems are pressurized. While you might get some dirty water into the cistern, it wouldn’t force any water back past the fill valve in the cistern and against the supply pressure. The cistern itself isn’t pressurized so any leakage of the valve is FROM the clean water pipes Even if you did, you would flush it out when you next hit the flush button.
There’s a reason that they require anti-siphon valves and backflow preventers on just about any system that crosses from potable to grey or black-water, including irrigation (which is pressurized) and water storage systems. For the toilet, the air-gap between the tank and the bowl is the only real protection in the system. All it takes is a pressure loss (or even equilibrium) in the system to allow backflow from the contaminated tank.
Once the water in the tank is contaminated, ALL of the tank components are contaminated. If at any time the fill valve is open there is a pressure loss in the system, you can have backflow. Also, the now contaminated tank side of the fill valve is in physical proximity/contact with the freshwater side. Yeah, it’s not an open flow, but it’s still a source of contamination.
I’m not saying you are going to die if you ever use this, and in reality the risk is fairly low, especially if you disinfect the tank after using it. But it is a real hazard, and shouldn’t be dismissed out of hand.
On all of the toilets in our house you can cancel the flush before its completed. The button/lever actually is labelled “stop”. We’ve had guests from the US which were amazed by this functionality.
~Raises hand~
I’m guessing you’re not in continental Europe?
I’m within the EU.
I tried googling to find why the mechanism isn’t more widespread or what it’s even called but I cant find anything (though literature on toilet regulations isn’t really very captivating reading). It also works well for conserving water as you can judge by yourself to how much is necessary.
I could have used that feature. Usually it is how fast can i get the wet/dry vac going. The answer is never fast enough - but usually not catastrophically late. - helps that it is in the closet across from the toilet.
Someone’s going to figure out how to turn this into a hilarious but messy public-restroom booby trap; then watch the authorities close down half of downtown.
Well better plastic coating than the old flush the potassium down the toilet.
The comments were funnier when this was on the front page of Reddit last night.
squarely in the plunger is a better option camp.
Thanks for your response. You’re right: it’s a great feature. At least with the push-button option now, you can let up or keep holding down as a manual way of using only the right amount of water, but an actual stop button is genius.
Theoretically yes (perhaps). But the risk would really only arise if you left the cistern (tank) full for a period that coincided with a loss of pressure to below the (negligible) pressure in the cistern of the clean water system. Furthermore, in most systems I’ve looked at, the inlet to the cistern is high on the side of the tank and is not even reached by the water level in the tank (depending on how the float is calibrated, of course). The cistern is also effectively cleaned each time you flush. I still don’t see it as a material risk.
