Is intention and a sincere will required for ẓihār to occur, or does it take effect even if it was merely by way of narration, similar to divorce?

Dhihar and divorce do not take effect if they are merely recounted, unless the one recounting intends dhihar or divorce. Each of them has its pillars, and the wording for each can be explicit or implicit. The explicit wording causes dhihar or divorce to take effect without the need for intention.

The explicit wording for dhihar is: "You are to me as the back of my mother." Its implicit wording is: "You are to me as my mother."

The explicit wording for divorce is that which contains the word "divorce," such as "divorced" or "divorcee."

Mere recounting does not cause anything to take effect.