I'm reminded of a visit from friends of mine when their child was about 18 months old
After dinner, the child got off their chair and started wiping their hands on the sofa
The parents repeatedly said "No, don't rub your hands on the sofa", and after being told about 8 times, the child did indeed stop.
"See", they told me, "if you repeat yourself and maintain the message children will listen and do as they are told"
"He stopped because he'd got all the custard off his hands", I replied
Luckily the parents have grown up a lot since 🙂