Cue the obligatory book recommendation, which I myself got from HN:

“Mutant 59: The Plastic Eater” by Kit Pedler and Gerry Davis, published in the 1970s. Explores the concept of a plastic-eating bacteria accidentally released in London, leading to a crisis as the bacteria starts consuming all plastic materials in the city.

So how long until I can recycle my scrapped PLA prints using my washer?

PLA is made from organic starches --- not hydrocarbons. So it is not surprising that it can be broken down easily.

I expect this may be used like Agent Orange was, but to destroy the enemy's cheaper 3D printed items.

Don't think PLA is a good choice for coffee cups