"Ephraim is joined to idols; leave him alone!" NIV translation
When God uses the name Ephraim to refer to the nation of Israel, it is a sign that He is not happy with them. Here, we see that He is not happy with them because they have turned from Him to worship idols and God says to "leave them alone".
Like the stubborn cows in the previous verse, you just have to let them go and wait for them to turn on their own and that is what God is saying here. It is easy for us today to say that we would never turn from God to worship man made things but every day we need to examine our hearts to see if that is true or not. Idols can come in many forms (houses, cars, family, fame) and not as just wooden statues.
"Even when their drinks are gone, they continue their prostitution; their rulers dearly love shameful ways." NIV translation
Even when they see God removing His blessing from them, the people (even the rulers) love the sin and hang onto it. This verse reminds us that we have to come to a point where we see how awful sin is in God's eyes before we can repent and ask for forgiveness.
"A whirlwind will sweep them away, and their sacrifices will bring them shame." NIV translation
Without repentance which is a change of heart, there will not be any way to be saved from the coming judgment. All of the religious activities will do no good and, in fact, will bring shame on them as they cannot say that they did not know any better.