Paul never said this,

Apostle Paul in the light of this said “I put myself under subjection so that I will not preach the gospel to the people and on the last day I myself become a cast away.

You said this:

Everytime we channel the word of God to the wrong location, we are simply making the word of God to become ineffective.

That makes no sense.

Even if we share the gospel with those who reject it we make them more accountable before God.