We empower our thoughts by focusing on them: by battling them, by pondering them.
By refusing to pay attention to them, they dissipate; they self-liberate.
Consider thoughts a byproduct of living that we manufacture, like methane or carbon dioxide. When we keep it inside, inside our brain in a little cage made of attention, we never let the idea release. These thoughts then agitate and drive us.
It is not that thoughts themself are poisonous or toxic; it is our attentional focus that retains them until they replace silence and cloud our desires that harms us.