I didn't say it's right. But at least you're not basically torturing the person while they're dying! You've seen what those bodies look like, and we know they're alive throughout the entire thing. Killing them during execution isn't right, but you know it's not on the same level as that.

[ since, you know, people tend to go for quick and painless deaths for executions. ]

Let's say that we do go and kill Vriska. If anyone had found my bottle before I did, then they would have seen the note. It wouldn't put two and two together for them to figure it out, and I'd be the obvious suspect. You know they wouldn't pass on choosing us for execution just because she was a Siren.