PillowflexSynthetic Down Pillow Inserts For Shams Aka Faux / Alternative 30cm x 40cm (12 Inch By 16 Inch)

All reviews I've read say the pillows look great, but has anyone actually used one? You know... for sleeping, or are these just for filling shams?

Can these be washed in the washer and dryer?

I also need to purchase inserts for a 20x26 standard pottery barn sham. should i order the 20x26 insert?

My lumbar pillow cover is 12X 20... I only see a 12 x 24? should I use this?