"Effective" seems to be a flexible word

I was tasked with getting some frozen lima beans, but failed. A vague memory said they could contain toxins that had to be cooked away, which might make them a less-than-safe product to stock in the frozen foods aisle. That turns out to be true, even for the US varieties which have about 30x less cyanide (100-170mg/kg) than those found elsewhere (e.g. Mexico). (Also true for butter beans, apparently.)

Boiling in water for long periods of time (>30 min) in a large excess of water is the most effective method for reducing cyanide (80% of the original cyanide will be removed).

So "effective" means you only have 20-30mg/kg of cyanide in the beans. I used to wonder why the canned limas were so mushy--they must cook the heck out of them.