It's different but if I understand what you are trying to do you can simply hold "OK" button on the line of text you wish to blow away then select the entire line (it will be highlighted), push backspace...all gone.
Yeah, that didn't work for me either. For most text apps, if you press and hold on the text, it will highlight, you can move the cursers to define the exact portion you want highlighted and then you can either do the back-delete key to delete or press and hold in the highlighted text to bring up a menu to cut, paste, copy, delete.