Future teachers face the challenge of whether and how to address their students' misconceptions--naïve concepts that often conflict with the correct scientific concepts taught at school. We developed a short-term digital training intervention on instructional knowledge about strategies for addressing students' misconceptions in physics. It comprised cognitive modelling of three instructional strategies (i.e. ignoring, refuting, and integrating) and self-explanation prompts. In a web experiment with 58 teacher students, we found that our digital intervention fostered learning processes (self-explanation quality) and learning outcomes (knowledge about three instructional strategies). It can thus help teacher students to acquire initial knowledge about how to tackle their future students' misconceptions. Self-explanation quality mediated the intervention's effect on instructional knowledge both immediately and 3 weeks later. These mediation effects emphasise the impact of self-explanations while learning from complex cognitive models. Finally, the intervention's positive side effect of reducing participants' own misconceptions is an additional practical advantage.