Milky spore works well, in my experience. And, I know people hate the beetle bags, but I have to say I've had success with them. They have to be thought of as more of a preventative than an instant solution.
We live in the middle of 21 acres, so no neighbors' gardens to pull the beetles into our garden and bag, which may be different from those who live in urban areas. A few years ago, though, my husband saw one and got it for me, just a spontaneous gift. I inwardly cringed, but hung it up so as not to hurt his feelings. It was nearly full in a week. Great - less beetles, I thought.
The real surprise was the following year - there were very, very few beetles in my garden. I thought about it, and realized that all of those beetles that were captured the year before were not alive to propagate! So, I got another bag and hung it up. The next year, even fewer beetles.
So, I now get a bag every year, and since I started using them, my flowers are beautiful and nearly beetle free.