SPOILERS are ahead for Beware Boiúna, now in theaters. Being one of horror’s final girls is no joke. It often comes with a lot of screaming, fake blood splatters and being chased over and over. Kiana Madeira has earned the badge of “final girl” for the second time in Beware Boiúna after previously earning it as part of the Fear Street cast. While a lot of her scenes looked very gross, she told CinemaBlend about why at times it felt like she was at her very own “spa day” on set. Yes, I thought that comparison was unexpected too.Beware Boiúna is one of the latest of new horror movies to arrive on the 2026 movie schedule just in time for spooky season. In the creature feature, Madeira plays Lena, an Amazon native who guides a group of doctors on a routine humanitarian mission. She had this to say to CinemaBlend when asked about spending prolonged periods in that gnarly mud in the movie: Being in the water and the mud helped my performance because it was real! It was uncomfortable, in the best way. The mud was made of safe ingredients, including collagen, so my skin and hair were glowing after that ;) Oh my goodness, what? Here I was thinking that Kiana Madeira was having the worst time filming those scenes when in fact she was being bathed in collagen! If you’re not familiar, collagen is often credited with its ability to improve skin moisture, smoothness, and elasticity along with contributing to improving mobility and helping with joint pain. It also can improve nail and hair growth and support bone density. So Madeira’s mud bath must have been actually super revitalizing. As she added in our email interview: The hardest part about working in the mud was acting like it was quicksand. I researched how quicksand works and learned that moving causes you to sink further into it. So as much as it felt like a spa day, I had to make sure I wasn't getting too comfortable and remember to incorporate the physics of how quicksand operates.Yeah, that sounds like one acting test for the 33-year-old actress. Still, she absolutely sold it in the horror film revolved around an ancient giant serpent! When we asked her how it felt to be able to take on the role of final girl, even over Happy Death Day’s Jessica Rothe, who plays one of the doctors named Alli, she said this: Truly, sharing the screen with Jessica Rothe was an honor and a joy. She's such a generous scene partner, and we had so much fun working together. Once I was solo, I didn't feel any pressure. It was more of a determination to finish the film strong, and I also had so much work to do; some intense scenes followed Alli's death scene, so I had my work cut out for me. My character Lena's arc was one that really compelled me, so I was locked in and focused. It was such a wild ride, and I loved every minute of it.In a year full of excellent scary movies, Beware Boiúna did a great job of providing the immersive scares and getting us scared of what secret creatures could lie in the Amazon. CinemaBlend also spoke to the movie’s director Mike P. Nelson, who told us about how that botfly extraction scene was done practically, and how it’s based on real life. I don’t know about you, but after hearing Kiana Madeira’s “spa day” story, I kind of want to take a dip in the same mud bath she did.