So when their precious little angels flush toys down the toilet they pay for it to get snaked, and when Spot chews up the blinds they pay to replace them.

It feels like money flushed down the drain because the carrier holds all the marbles.

That said, ...You may have toilet float / flush valves ("flappers")  that need to be looked at or faucets that don't shut off fully.

Do you count how many times they flush the toilet?

there were some pretty good deals over in Yuba city a few years ago not sure if they have flushed out and risen in value..

(ouch...insert image of deal flushing down the toilet bowl).

I think it's very reasonable: pleople flush all kinds of things down the toilet and then expect me to pay a plumber to fix it. 

That way I can schedule little problems at my convenience rather that getting the Friday night call that the toilet won't flush any more (and hasn't since Tuesday, true story).I don't trust my tenants to repair my properties.

To me the only exception would be if they clogged drains by flushing paper towels or damage caused by abuse like punching a wall.Guess what happens when her sink starts leaking next....she doesn't want to get hit up for $100 and let's it drip drip drip and now a small repair could be thousands in damage.

That or, if the kid is using tons of TP, they need to learn to do multiple flushes.