I just finished putting to sleep 2 honey gourami, 7 threadfin rainbowfish and 1 female betta. I've also lost 5 other threadfins due to TB this week. I slowly added clove oil to the bucket they were in, and when they were unconscious, I added vodka until there was no more gill movement.
My tank looks empty without them, and they were lovely fish. I'm sure sad to no longer have them.