This is a common misconception. It requires much much more energy and delta-V to send a craft on a collision course with the sun than to send it to Mars, or even to send it outside the Solar system altogether[1][2].

1. https://www.reddit.com/r/askscience/comments/5lt50r/why_does...

2. https://en.wikipedia.org/wiki/Delta-v_budget#Interplanetary