Avoid using your camera to delete photographs.
Let's look at two reasons.
You can't always make judgments using the LCD screen.
1) The screen is small.
Some photographs look good small.
Some look highly delete-able when they're only 2 inches wide, but look delectable when view on a monitor.
2) The screen has low resolution, and may have inaccurate color.
If your tired or hurried, you may inadvertently delete all of the photographs on a memory card.
Yes, do delete the obvious duds, if you wish.
But wait to delete other photographs until you're at your computer.