"I would have done X if Y would Z" or "I would have done X if Y would have Z"?

Question

What's the correct construction?

Example sentence:

"I ate the goldfish," I would have confessed if those words wouldn't sound crazy.

"I ate the goldfish," I would have confessed if those words wouldn't have sounded crazy.

Which is the correct alternative and why?

Note: I checked Google and I think there's a third option: I would have confessed if those words didn't sound crazy.

Answer 1

I would confess if those words wouldn't sound crazy.

I would confess if those words didn't sound crazy.

I would have confessed if those words wouldn't have sounded crazy.

I would have confessed if those words didn't sound crazy.

I would have confessed if those words had not sounded crazy.

These are all idiomatic.

Answer 2

You are correct with the third option. It should be : I would have confessed if those words didn't sound crazy.