I believe that if I have understood you and I still think that it can work ...
In the video I have uploaded, the dialog line "hello" has a value of -1 to be displayed. When you use it, change the value to -2 and it disappears. When he speaks again, you set the value to -1 in "actions" so that it will be shown again.
You do not have to leave the option to delete the dialogue part entry checked
Hopefully we're talking about the same ... hahahaha