Don't worry about painless or not. It's right after they die and they face their maker that their 'entertainment' begins. All will be made right in the end.

I hate the political part of execution anyway. We put down thousands of pets every day painlessly. Really good drugs for the job are available but politics prevents their use.

“In a time of deceit telling the truth is a revolutionary act.”
― George Orwell

It's not over when you lose. It's over when you quit.