You are WIERD!! Why don't you throw a party, invite the condemned sim and put them in a dark room with no electricity..or doors or windows.....Or better yet, put them in a pool, delete the ladder and then it can spend the rest of it's ghostly life puddling all over your lot and destroying everything in its path.
Faster to cremate them by putting them in a sealed room and placing some "buyable fire" in there or one of those flame pots from NL.
Ever tried drowning a sim? It takes forever.
One could also "Influence to Take Cake" from a cow plant and reap the benefits.
I found those firepots make exceptionallly dramatic executions. I once made a glass walled chamber 8x8 with a fire pot on every square. The condemned had fallen asleep on the floor, so I turned on all the pots in pause mode so they would fire at the same time... he slept for a little while in the flames and then woke up and caught fire. It put me in a great mood all day!
Author