I read some people's comments about sticking q-tips in cats and rubbing the sides of their behinds. As a rape survivor who has had object shoved in my vagina, I can tell you shoving objects inside your cat will cause pain and nerve damage. In my case it is permanent nerve damage, and it could be permanent pain and damage in your cat's case as well. Your cat cannot scream and say "stop, you are raping me"so I have to say it for her. I love animals and no animal deserves to go through the pain and torture of rape.
Since your cat cannot speak, she cannot give consent, so when you stick things in her or grope her while she is in heat, you are raping her. This is an animal abuse felony. It carries less years in jail than a human rape but it still is a felony. Do you want to be a felon? I always used to say to the felons who raped me when I was a kid, "I want to grow up to be a veterinarian, do you have any dreams for your life, or do you think you will enjoy being in jail for the rest of your life?" Sometimes this made them stop, and sometimes this made them punch me in the head until I was unconscious.
The best thing to do of course is to spay a cat before they go into heat. It is good to be a responsible and kind person. Drowning kittens will make you cruel and apathetic towards the suffering of animals and the sociologists who studied battered women in shelters found a correlation between pet abuse and murder and the abuse and attempteed murders of women living there. Basically if you start by drowning kittens and raping cats, you likely will end up battering and raping women. Animal abuse leads directly to human abuse. Abusers get bored treating small animals as their prey so they go after humans. Eventually no one will love you and you will die alone.
There is a way to calm a cat in heat that I just found out today. I am staying with some friends and their cat is in heat. She was writhing around and looking uncomfortable. I thought to myself that maybe she is in pain. Cats have nerves and cats feel pain. Maybe being in heat is a painful or uncomfortable experience. So I just petted her gently on her head and back and I prayed quietly to God to bring an end to her pain. I asked God to heal her. I spoke Shalom over her body several times. Shalom means peace. After a few minutes, she was quiet, calm, and was not writhing anymore, so I praised the Lord. Just ask yourself "What would Saint Francis of Assissi do?"
You know the Bible forbids bestiality, due to the fact that it is a heinous form of animal abuse. So just pray to God and God can bring peace to your cat. God uses animals to bring spiritual messages to people and God has complete control over every single animal. Just ask God to bring healing and peace to any animal that is in pain, writhing, uncomfortable or lonely, and He will. He is a God who loves all of His animals and people.