Persuading to persuade

A big challenge for my year 5/6 children was our work around persuasion or argument. We worked on different topics around what we had been learning - The worst disaster is...? Our school is the best? down to persuading the teacher What wet weather games the class should spend their $200 allowance on?
But it wasn't until we hit on the more abstract and fun that I really saw the enthusiasm increase.

Children enjoy the bizarre and the creative.
Our hit topic actually came from a relieving teacher (using the conversation as a time filler/winding down at the end of the day) The noise level and involvement of the children was at maximum. So I ran with the idea for the next few pieces of writing with much improved results.
Would you rather eat a mouse or a cockroach?
Which is the best pet - an ant or an elephant?

The amount of prior knowledge the children could bring to the topic meant they had plenty to say, and the discussion with others who disagreed meant children were able to mention and negate any negatives to their side of the argument into their writing.

Using the bizarre and the oral language preparation proved a winner this time.
Has anyone else had the bizarre topics motivate writing?

An example below - this child is a very reluctant writer - usually completes a sentence or 2 under duress. This was finished in 30minutes -( I have edited for spelling and punctuation)

I would want a pet any more than a pet elephant. To begin with an ant is a better pet than an elephant. One off the reasons is - how are you going to feed it? I mean it must eat 2 tons a day. But an ant needs to eat a crumb for  3 days.

Yes, you can ride a elephant, but will the road hold it’s weight? If it cracks you will need to pay.   At a traffic light the elephant won’t stop and it will crush the car’s and  probably kill someone. You will have to pay for the car and the funerals and you will go to prison for manslaughter and the elephant will go to Africa.

Now the poo, how are you going to get rid of that?