I'll surely do that, but I'm not out there all day!!!

Some more info here: http://www.extension.umn.edu/garden/insects/find/japanese-beetles/ (this is from the U. of Minnesota but I'm sure it's good info wherever you are).

I'm in MD, 60 miles south of DC at a river.

Actually, I got so fed up with them that I dug up all the rose bushes and trashed them. Japanese beetles just love them and it draws them to the rest of my garden. One rose bush did come back, I guess that I didn't get all the root out, and I just don't have the heart to destroy it with that will to live. So I end up back out with my soapy water.

I figure that the soapy water doesn't stop them from coming, but it does stop those ones from breeding. And it is non-toxic to anything else that might be in the garden. The biggest problem is that the next year, there are just as many as there were the year before. I know of nothing that will keep them from coming.

but I AIN'T gonna do that. Found this, to maybe help you dealing with 'next year<'

Prevent: Although the following solutions won't provide immediate gratification, you will be better off next year. Grub Guard kills the grubs that turn into Japanese beetles. Ideally, apply it in spring before the beetles emerge. The second half of this 1-2 prevention punch is Milky Spore, which also kills grubs. It takes a year or so to get established in your soil, but it keeps working for 10 years or more.

I have always wondered how many of the beetles in my yard were grubs in my yard. How far do they travel? The three years that it took my rose roots to produce a plant again were three years without any Japanese beetles in my yard, so they went somewhere else, and they came back from somewhere else. I am not sure how this would work, but it is worth a try.