Have the courage to stand up for what you believe in, even if it terminates your employment status. I'm only unkeen to have my name on this, because I haven't done it, and I wish several times in the past, I had. I respect the person who did this early in his career in one ISP immensely: it was stunning to watch somebody say "you're full of shit" to the new CEO, and walk out. (he was btw, full of shit)
I've done similarly career-threatening things in the past and my strongest advice is to stand and deliver in an actionable way . Telling the CEO he is full of shit is not actionable. Telling the CEO that his plan will not work and that to save the situation he needs to do XYZ is. If you've judged the situation correctly and that level of drama is actually necessary, then either they will respect you and do it or they…
Another possible/likely option - they'll pay lip service to your plan, convince you to stay, and then gradually slip back to the full of shit approach they originally intended.