You could uninstall demo contents from your site. If you import different demos so many times, you could see some posts are overridden by new ones. In that case you need to uninstall imported demo contents before importing new demo. You could remove all contents from previously imported demo or remove only some parts such as pages, widgets and so on.

Please backup your site before uninstalling. All imported and overridden content from Wolmart demos would be removed.

All – Remove all content.

Pages – Remove pages.

Posts – Remove posts.

Attachments – Remove images.

Products – Remove products.

Builders – Remove templates for header, footer, popup builder and single product builder.

Widgets – Remove sidebar widgets.

Theme Options – Unset theme options.