Temporarily prevent a full toilet bowl from draining

The toilet bowl can only hold water as high as the top of the porcelain inside of chamber 5 in the picture below, unless you do something to stop it:

Wad up a large trash bag and stuff it into the bowl, about as far as it will go. If it's not large enough, place a few crumpled paper towels into the bag and re-wad. It should be large enough to clog most toilets, it's easy to remove, and won't seep like a towel or rag would.

Fill small plastic bag with one quart of water, remove excess air from bag and tie off. Place in toilet bowl. Dispose of bag when finished in trash receptacle.

I would try a child's balloon. You'll have to wedge it in tight so it doesn't float up. If you can't wedge it....try a water balloon.

In either case, with a string on the balloon tied to the flush handle or toilet seat.

I got it done but it is not as easy as one might think. Most of the time there remain some gaps water uses to drain out, and after a couple of minutes, water level is back to normal. So it is required to apply some kind of pressure all around the toilet bowl.

The best solution I have come up with involves using a garbage bag and a plunger.

• Fill the garbage bag with water at 25% and stick it down the hole.
• Put the plunger inside the bag so the bag adheres to the bowl, as depicted below.
  • If you press hard enough, it should be sealed tight enough.

Even with this technique, water level only holds for 1 or 2 hours, which is barely enough for cleansers to do their job.

Here's a completely different solution - to stop the water leaving, stop the air getting in. It will be fiddly but significantly reduces the risk of getting something stuck half way down.

• Cut a sheet of heavy plastic sheet that fits tidily over the top of the open toilet.
• Tape the edges all round smoothly and evenly with duct tape, leaving the front flapped back and having more tape ready.
• Fill through the opening.
• Flap down the front and tape.

If you can make it airtight the level will stay high indefinitely. More likely a tiny bit of air will get in but it will still hold for a few hours. Use clear plastic sheet and you'll be able to keep an eye on it. Untape carefully starting at the front, and you'll be able to stick it back down if the first treatment wasn't enough.

i hate to just plug a product but on tv flex tape looks like it may work. he literally takes a piece and pluggs up a above ground pool by taking a piece of the tape and literally plugging it from the inside of the pool. so the tape can get wet and still stick. enough pieces, im sure would make a perfect seal. and then just peel once done.