The eye-watering task saw the intrepid duo don the swimwear made famous by Sacha Baron Cohen's comic Kazakh character - known for his catchphrase: "Is nice!".
Thong Song singer Sisqo, 31, is obviously used to skimpy garments.
But bashful Alex, 34, was evidently worried that his bulges weren't big enough and stuffed APPLES down his pants in preparation.
Hollywood actor and born-again Christian Stephen Baldwin, 43, refused to don a mankini - deciding to sport a pair of Speedo swimming trunks instead.