While it's important to maintain good hygiene and cleanliness in shared spaces, it's understandable that you may want to approach the issue in a humorous way. Here are a few ideas for the text of your sign:

1.  "Attention Non-Flushers: Our new course will teach you how to use the flush switch. No experience required!"
2.  "Flush like a pro! Our training will take you from a novice to a master in no time."
3.  "Do you struggle with the flush switch? Our course will make you a confident flusher in just a few short lessons."
4.  "To flush or not to flush? It's not even a question with our training course."
5.  "Don't be shy, give it a try! Our flush training course will have you feeling confident in no time."

Remember to keep the tone light-hearted and humorous, while still getting the message across. Good luck with your sign!
spam fails_task lang_mismatch pii not_appropriate hate_speech sexual_content quality toxicity humor helpfulness creativity violence