Clear cookie for dynamic landing page

Marketo developer has designed dynamic landing page based on language and country segmentation. While testing using segmentation prefix to test dynamic landing page and this is working fine. But, when using the same landing page without prefix in email and testing for multiple languages then data is sync to previous lead. Only, If user delete the cookie then do test again then data sync is happening correctly.

Is there any Marketo JS available  that helps clearing cookies in this case so that data sync happen to correct lead without doing this clear cookie manually?  I read few available reference link in community but did not find exact same thing.