The way I’ve done this is to create a custom state and add the customer to that custom state when the checkbox is checked, and remove the customer from the custom state, when the checkbox is cleared. Then, the Delete button, deletes the contacts found in the custom state, either through immediate action, or an api workflow.
Here are the events that populate the custom state:
And then I use an api workflow to perform the delete, and reset the custom state:
And here is the api workflow:
This allows you to delete (or perform other such actions) on a group of things all at once.
@seanhoots has recently created a plugin for shift select capabilities to make the process even easier for the user.