Dual National - Double Visa Free? Hi,

This question is somewhat theoretical as it's not yet certain if the Vietnamese government will renew the current 15 days visa free for tourists beyond 30th June 2017, but could I theoretically enter on a U.K. passport for the 15 days, leave, and then re-enter on the French passport and get 15 days visa free within 30 days of having entered on the British passport?

I don't necessarily plan to do this but just curious in case it was possible.

Cheers