It's not a clever hack any of us want to have to use, but the Art of Manliness blog has a homebrew fix for the next time your restroom trip ends in disaster.
When a toilet clogs, the first jobs are stopping water from flowing to prevent an overflow and finding a decent plunger. Then again, if you're visiting a friend's place and feel might embarrassed returning from the bathroom with such a request, some hot water from a bathroom sink, and dishwasher detergent, if you can find it discretely, can put things right:
Add a few cups of hot water to the toilet bowl before you start plunging. After you pour the hot water in, let it sit for a few minutes. To put it mildly, the heat helps break the, um, stuff up. This will make unclogging the toilet with the plunger much, much easier. The heat from the hot water can sometimes break up the clog without plunging, so this could be a good tactic to use if you a clog a toilet at a friends house and you don't want to face the embarrassment of asking for a plunger.
The blog post offers more good-to-know tidbits about properly using a (warmed and un-stiffened) plunger and using tools like an auger for the really bad, um, breakdowns. If you'd care to be so discrete as share your own toilet emergency fixes, we'll welcome them in the comments.
How to Unclog a Toilet Like a Plumber [The Art of Manliness]