If you want to delete your all post at a time this plugin will help you to do this. Go to Delete Post settings page selece a post type then click on Process Delete button. Then it will show a report, Now if you want to delete post just click Start Delete button. Done! If you need more feature on this plugin, Please send me a mail sourovfci@gmail.com i will add your feature. This plugin is also in github https://github.com/sourovroy/delete-post-swrs