"All known techniques are defeated by our organs' capacity to regenerate, like my daughter's hand."

That seems to be a perfectly acceptable factual claim that no known scientific technique can answer.

The only known general effective technique for distribution is Commitment ordering, which was disclosed publicly in 1991 (after being patented).

It couldn't be detected by any known experimental technique.

The only known technique of prevention is to avoid ingesting the poisonous alkaloids.

There are no known techniques for altering the growth of plants in this way.

I used known techniques and I invented my own.

Another known technique to turn something into Varuga is by cell-infusion.

It was a painstaking history of every known forging technique.

Trace scheduling is one of many known techniques for doing so.