Octave plots - how to flush out the plot (is it a pipe still?)

Question

I am running Octave 4.21 - it works great, however, the command purge_tmp_files does not execute. I just want to make sure that when I run a script, that the previous script's run is completely "forgotten". Is there some command to replace that or is there a way to flush things out by closing some handle? I haven't really read up on the graphics system much - my bad for not knowing how to reinitialize the figure so it draws cleanly. I'll offset a piece of text and I wind up with two pieces on screen - the old and the new. That's all.