Some interesting examples on how the writing and the erasing are almost one.
The Halachas of Salting Beans and Lentils;
Various important examples which come up on Shabbos in conjunction with the halachas of perfuming or putting in a nice smell into an item;
Eating Hard Food When It Might Make One's Gums Bleed, and Removing Meat Stuck in One's Teeth When Gums Might Bleed;