I made a 3'x3' box a long time ago, had about 100 pounds of cat **** litter in it w/ a fine mesh reinforced screen about 1" down from the top of the box, saved so much time cleaning and no missing or "lost" bolts in the drain pan. Also, tranny fluid is not harmful in moderation to humans or animals( makes em wet **** alot) however its the anti-freeze and mainly the green kind thats toxic, im not sure on the dex-cruel ****.