Perhaps this applescript might be useful?

tell application "Microsoft PowerPoint"
        set target_folder to choose folder with prompt "Select the folder containing your PowerPoint files:"
        set powerpoint_files to (get every file of target_folder whose name ends with ".pptx" or name ends with ".ppt")
        repeat with a_file in powerpoint_files
        open a_file
                tell the active presentation
                        set slide_count to the count of slides
                        repeat with i from 1 to slide_count
                                set the_slide to slide i
                                tell the slide transition of the_slide
                                        set automatically advance after to 0 -- Set automatic advance time to zero
                                        set advance on mouse click to true -- Ensure it advances on mouse click
                                end tell
                        end repeat
                        save
                        close saving yes
                end tell
        end repeat
end tell