You can just keep deleting their post.
In 10 minutes I had to deleted same post 4 times! It seems he is quite now but the attitude is being shown by him, I guess he will take the opportunity of 24 hours time too.
To reply a post he comes up with an off-topic and according to him:
It's all right, do what you think is right and what you personally like, unless of course it violates the rules of the forum.
As long as it does not violates the rules of the forum then it should be alright. If someone has this tendency then obviously now they will take the chance of 24 hours time since the loop hole will keep them safe.
I created a bot for the exact problem you are describing. Please see this
thread.
My bot will automatically delete posts made by certain users you do not want posting in your thread.
You're welcome.
Thank you. But I do not mind him to post as long as it is on topic or I could use the bot gladly.