While I was searching for the rules governing the omission of relative pronouns, I found the best explanation in the previous answer.
According to a 'null-relativizer’, I was wondering whether the following sentence makes sense.
Original sentence: That way, they create a perception of honesty from which they can be more persuasive about the strengths of the product. (excerpted from a textbook)
-> That way, they create a perception of honesty they can be more persuasive about the stregths of the product from.
As far as I understand, this form can be possible because the relative pronoun "which" can be omitted as an object of "from".
Please correct me if I am wrong.