We camp a lot, and over the years, we had problems where the soap from the scrub brush would leak out on everything in the camping box. So several years ago, I came up with a solution, and thought I'd share.
First, I took a 32 ounce cup from my favorite convenience store, and then cut a hole in the lid big enough for the handle to go through.
Then we could slide the handle through the lid, and close the lid onto the cup. Then, when it's put into the camping gear box, soap rarely leaks out now, and when it does, it's contained in the cup.
We've had to replace the cup ever so years as the plastic of the lid becomes brittle, but considering I'm taking something I already have on hand, and turn the trash into something useful, I think it can't really be beat!