After you make the change, you will need to ‘rebuild html’ on the post with the onebox. Otherwise you will see the cached version of the OneBox.
Click the 
under the post to find the ‘rebuild html’ option
After you make the change, you will need to ‘rebuild html’ on the post with the onebox. Otherwise you will see the cached version of the OneBox.
Click the under the post to find the ‘rebuild html’ option