I’d definitely check the care instructions before putting the whole blanket in a home washer. With a heavier weighted blanket, the cover is usually much easier to wash regularly, while the inner blanket may need less frequent cleaning. I’d use a gentle cycle, cold water, and avoid harsh detergents or fabric softener. For drying, air-drying flat seems safer than putting a 15–20 lb blanket into a dryer, especially if you’re concerned about the stitching and glass beads. I bought mine from Novaline here:
https://novaline-blankets.com/ So far, keeping the cover clean and washing the inner blanket only when necessary seems like the easiest approach.