I'm not entirely sure specifically what a 'doppio senso novel' is. It could potentially be a novel that has a double meaning or two different levels of interpretation. But without more context, it's hard to be definite.
Sorry, as I'm not sure exactly what a 'doppio senso novel' is, I can't recommend any. But if it's about novels with dual meanings, you could start with some works by Franz Kafka like 'The Metamorphosis'. It has a literal story of a man turning into an insect, but can also be seen as a commentary on alienation and the human condition.
One benefit is smoother skin. As seen in many full body wax stories, people love how their skin feels so soft and sleek after the wax. Another is that it can make you look more toned. For example, in the story of the bodybuilder, it enhanced the appearance of his muscles. Also, it can give a boost of confidence, like the girl who went on vacation. She felt more confident showing off her body on the beach.
House of Wax is purely a work of fiction. The plot and characters were created for the purpose of entertainment and not based on any real events or people.
One important tip is to not be over - confident. Just like in my story where I thought I could do it easily after watching tutorials. You need to be really careful about the amount of wax you use. Too little and it won't work, too much like I did and it's a mess. And if possible, have some wax remover handy in case things go wrong.
One horror story could be about getting a really bad burn during the waxing process. Maybe the wax was too hot and it left the skin red and blistered. It was extremely painful and took a long time to heal.