I put bone char in a used Whole Foods salad bar container and stepped on it many times to crush the char. Then I put it below my flow thru to catch the drips. A week later and the drips are still puddled on top of the crushed lid. It has not soaked through. The manufacturing process must make the material so compact that water does not soak in quickly. A previous container torn into one inch pieces did not seem to last longer than egg carton.

Here is a link that might be useful: Whole Foods Salad Bar Container