Go Jo hand cream and a washcloth takes it off with no effort basically. It is a cheap and non chemically hazardous way to remove it without removing the paint or number stickers.
Getting it off as soon as poosible accomplishes 2 things
1) it lets people know their vandalism won't be seen by others
2) if others see you REMOVING it it will hopefully keep them form thinking about marking them to begin with.
It has worked for me in Miami, Tuscon and here so far.
Father of Future World Champion Lorelei Johnson #13697