Those should be easy, lets make them a little tougher.
Photos swiped mostly from the fabulously gay duo (their words, not mine), Tom and Lorenzo, who have a 4 part series with most, if not all the contestants in their "native garb", here, here, here and here.
Answers below the fold:
Left to right, top to bottom, in white font - block to see:
Britain, Japan, Canada, Thailand, Russia, Greece, Costa Rica, Belgium, Myanmar, Singapore, Egypt, France, Netherlands, Slovenia, Tanzania, St. Lucia, Guatemala, Kosovo, Venezuela, Bahamas, Brazil
Last, the United States contestant, Nia Sanchez, who was first runner up.
Wombat-socho had the "Rule 5 Sunday: Wax Ecstatic" post up at The Other McCain before Superbowl night was over.