This is a Chilean slang phrase used as a dismissive expression and it roughly translates to 'go and wash your coat'. It's used when you want someone to stop bothering you or to dismiss what they're saying.
Examples
- Spanish: ¿De verdad crees que puedo hacer eso? ¡Anda a lavarte ese paltó!
- English: You really think I can do that? Go and wash your coat!