'I had a biohazard zone around me,' Benedict Cumberbatch said of not showering for 'Power of the Dog.'

Benedict Cumberbatch has a winning aura about him.

The British actor has received widespread acclaim for his portrayal of a ruthless cowboy in "The Power of the Dog," with most Oscar experts anticipating he'll be nominated for best actor for the second time (following 2014's "The Imitation Game").

However, when Cumberbatch initially landed on the New Zealand set of the 1920s Western (in theatres now, streaming on Netflix Wednesday), he skipped bathing to get into character. The film's director, Jane Campion, was originally supportive.

"My family hadn't arrived yet, so I figured, 'I'll just go for it,'" Cumberbatch remembers. "But then she'd ask me out for sushi or a walk, and I'd practically radiate — I was surrounded by a biohazard zone. Cuddling up to Cumberbatch and taking a photo was not a good idea."

Despite the fact that the "no showers" experiment was short-lived, he requested that his costumes not be washed: "Every now and again, they'd spray them with a little alcohol so they weren't lice-ridden, but I was peeling them off and on in all kinds of weather."

For Cumberbatch, 45, how he smelled was an important element of relating to Phil Burbank, a fiery rancher who works alongside his meek brother, George, who was "amazingly sensual" and "animal nature" (Jesse Plemons). Phil is overcome jealously when George meets and marries a benevolent widow named Rose (Kirsten Dunst). He begins to constantly disparage the newlyweds, as well as Rose's sensitive teenage son, Peter (Kodi Smit-McPhee), who develops an unexpected bond with his harasser.

"(Phil's) behavior is aggressive and repulsive, yet there's a hint of vulnerability," says Cumberbatch. "He can't tolerate it when this woman enters his brother's life and sees his brother beaming with affection. He's afraid, terrified, and acting out. This is frequently due to a sense of insecurity."

The slow-burning drama, which is based on Thomas Savage's 1967 novel, tackles powerful topics including toxic masculinity, gaslighting, and suppressed sexuality. While his fellow cowhands' roughhouse, bathe together and chase prostitutes at a local tavern, Phil bitterly watches from afar. Phil is progressively revealed to be lamenting a lost relationship by Campion.

"Jane's script truly draws you in and shows you a man who has never been able to love or be loved in his life," Cumberbatch explains. "He's a tragic figure," says the narrator.

"Savage examines the weakness of the alpha and the depth underlying who Phil truly is in his novel: the secret he had to keep and how the core of him was not permitted to be shared," adds Campion.

Cumberbatch's powerful main roles in the TV series "Sherlock" and "Patrick Melrose" convinced the filmmaker that he'd have the "huge personality" and "emotional compassion" required to play Phil. She also loved that the Londoner wasn't a natural fit for the role of a gruff Montana cowboy.

Campion laughs, "I thought of the person who would have the most difficult time executing it." "But it's true that if you offer an actor a tremendous challenge, they nearly always go above and beyond to fulfill it, rather than thinking, "Oh, I've got this." We all knew this wasn't in his back pocket, but he certainly has the acting chops."

During the filming of "Dog," Cumberbatch learnt a range of new abilities, including playing the banjo, braiding ropes, lassoing livestock, and making cigarettes with one hand. He also practised whistling, which Phil uses to frighten Rose whenever he enters or exits a room.

"That took a long time and a lot of patience from the people around me, particularly my family," Cumberbatch adds of his three "exceptionally gorgeous, fantastic" children with his wife, theatre director Sophie Hunter (Kit, 6, Hal, 4, and Finn, who will be three in January).

The actor is presently reshooting "Doctor Strange in the Multiverse of Madness," which will be his second standalone Marvel picture and sixth outing as the supernatural Dr Stephen Strange, for release next year. He's well-versed in keeping any information about the impending "Spider-Man: No Way Home" under wraps (in theatres Dec. 17).

"You know it's a dead-end," Cumberbatch grins, "but I can tell you this: It's a hilarious picture." "I don't want to reveal anything - and I haven't even read the entire screenplay yet! I did that on purpose because I'm simply looking for a good time."