What you're looking for is called "third party liability insurance" and is widely available worldwide. In the US it is usually sold as part of homeowners/renters insurance. Outside the US I've seen it sold as a separate product. Some travel insurance companies also include it as part of their package. It will cover accidental damage to other people's property and even more than importantly they have a team of lawyers on hand to scare off various scammers trying to charge you for no good reason. That being said, insurance is quite often a fraudulent product too and I strongly recommend avoiding to buy a policy without first finding several verified reviews where people received an actual payout after a claim. Unfortunately there's no such centralized website for insurance reviews, so you'll have to do some Googling for each insurance company.
Another option is often self-insurance. If you don't expect the claim to go over whatever you're comfortable spending in case of an accident, you don't need to buy insurance. A flooded toilet is probably a few thousand dollars at most, which might be okay depending on your income.
Finally some countries offer legal insurance where you pay a small fee each month and have access to a lawyer in case of a legal dispute. Having a lawyer send a strongly worded letter to the other party is often sufficient to stop them. If not, having a lawyer on hand is very useful to defend yourself in court. Remember that the other party can't just charge you willy nilly. They have to prove you're at fault in a court of law if you dispute their claim.