I did tonight. There was a pretty large cricket in my room, so I tossed a towel on it like a net and stepped on it several times. After lifting up the towel, it wasn't moving so I figured he was dead. I picked it up in a paper towel and figured I'd drop it in the toilet to flush it. I sort of had to use the restroom anyway, so I dropped the paper towel and then urinated without really looking. I then went to flush the toilet and saw that it was still alive and trying to swim, and I basically had no other option but to flush at that point.
So I stepped on it and badly hurt it. Then pissed on it. Then flushed it down the toilet to drown.
I literally feel like a monster, and really regret not killing it quickly or taking the paper towel outside.