Go wash vs Get washed

Is there a significant difference between these two sentences? which one is more appropriate when we have to tell our kid to wash his hands before having food.

1. Go and wash your hands
2. Go and get your hands washed

How these two sentences are different?

I personally never heard (2) (at least, for the verb to wash), but I would say (1) is more recommended, because it is more straight-forward and thus sends out the message clearer and faster.

Also, I would lose the and there, so it looks like this:

Go wash your hands.