I also made a kitty liter pot with a tidy cat 27 pd bucket that i fill up about 3/4 with soil and wrap the outside with the black stuff you put on a roof under the shingles (yeah its ghetto

) . It has 3 indented areas on the bottom, Two 1in by 4in and one big 5in square in the center.
Originally i put 6 1/4 inch holes in the middle indention and 3 on the 2 other parts. That killed my first seedling because the water would sit in the indented parts. So i put water in the empty bucket to see what was happening, water was standing under the indentions and not draining out.
I have added 3 holes on bottom of the raised parts and 2 on the sides of the indentions and put 3 holes on all sides of the center indention and made kinda like 4 troughs on on the far outside edge because the was raised even more than the inner parts. I put water in it and it all drained out.
I am waiting for my seeds and new potting mix i ordered to come in so i havent tried it with actual soil yet but i think i got it right now.