I've also seen Americans saying "Andale! Andale!" in similar circumstances. But which expression is more commonly used?

Native speaker’s answer
Rebecca
"Chop chop" is used much more commonly as it is usable in all forms of English. Its popularity is roughly ten times higher than "Andale". Ex: We have customers waiting, let's work a little faster. Andale! Andale! Ex: Chop chop! These dishes aren't going to wash themselves.