Advancing computational thinking in elementary education has been rapidly gaining attention due to the prospective of developing 21st century skills. However, interventions in this domain risk failure if they do not explicitly address the particular sociocultural traits of the deployment scenario. This is the case in most countries of Latin America, where computing has not reached a sustainable penetration in K-12 education. In order to bridge this gap, we designed a one-week workshop for advancing computational thinking targeted to 10-12 years old Chilean students with no prior experience in programming. This paper describes our intervention and presents the results of a qualitative study analyzing positive and negative aspects of the experience. Although most participants effectively acquired basic programming skills by the end of the intervention, we also identified several inaccurate views on computing and computer scientists. For instance, computing was mostly perceived as a set of informal experiences rather than a way for enabling creation, automation, and work. The word "hacking" appears to be used as a metaphor for more technical terms, such as "programming" or "algorithm". Finally, negative stereotypical views of computer scientists resulting from the intervention were not as frequent as initial perceptions. These results provide fresh evidence on how to design, adapt, and evaluate computational thinking interventions targeted to K-6 students in Latin America.