Disinformation about science can impose enormous economic and public health burdens. Several types of interventions have been proposed to prevent the proliferation of false information online, where most of the spreading takes place. A recently proposed strategy to help online users recognise false content is to follow the techniques of professional fact checkers, such as looking for information on other websites (lateral reading) and looking beyond the first results suggested by search engines (click restraint). In two preregistered online experiments (N = 5387), we simulated a social-media environment and set-out two interventions, one in the form of a pop-up meant to advise participants to follow such techniques, the other based on monetary incentive. In Experiment 1, we compared these interventions to a control condition. In Experiment 2 another condition was added to test the joint impact of the pop-up and the monetary incentive. We measured participants' ability to identify whether presented information was scientifically valid or invalid. Results revealed that while monetary incentives were overall more effective in increasing accuracy, the pop-up contributed when the post originated from an unknown source (and participants could rely less on prior information). Additional analysis on participants’ search style based on both self-report responses and objectively measured behaviour revealed that the pop-up increased the use of fact-checking strategies, and that these in turn increased accuracy. Study 2 also clarified that the pop-up and the incentive did not interfere with each other, but rather acted complementarily, suggesting that attention and literacy interventions can be designed in synergy.