Thanks for the explanation.
The barrels now are destroyed when they overlap with a slash. Unfortunately, when the barrels move, they can run into a fading slash and still be destroyed. Making the slashes fade faster solves this. But then the animation looks bad. So here is my work around:
1. Leave the slash object and behavior as is.
2. Create an identical slash object but make it invisible and have a very small fading time.
This does work but does anyone have a more compact solution?