Another possibility would be to override views/default/page/elements/header.php. If you don't want anything from header.php displayed, you could override it with a modified version that is empty beside the initial <?php line.

If the modification seems to have no effect, you might need to flush the cache in the admin area. And it might be that some other plugin (theme) overrides the view(s), too. So, you would have to make sure that your plugin that contains the modified views is placed lower in the plugin list.

Hey, thanks! It turned out my override was working. The cache needed to be flushed, but I missed that. Also your method works too. Thanks!