Somehow in most of the apartments I've lived the toilet was always really close to the dryer. So for many many years I would just throw everything from the lint trap into the toilet to be flushed next time I use the restroom. Without thinking about it, it seemed like 'organic' material. Probably most of it was (I tend to use the dryer mostly for towels and bedding, which is mostly cotton).

One morning it occurred to me that I've been flushing microplastics away, which is really terrible...

Catching particles coming from the wash seems like a pretty tough problem. Even if the washing machine could somehow catch these, I can't see consumers (and thus manufacturers) jumping at the chance to clean out dirty soapy goop from a washing machine filter... which I imagine will resemble cleaning out a shower drain trap pretty quickly.