I know a lot of BIAB brewer hang their bag over the kettle to drain, however since I am brewing inside, this isn't very practical. After one time of burning my hands trying to squeeze the rest of the wort out of the grain in a colander, I decided there had to be a better way.
The better way presented itself to me at my local grocery store...we asked for frosting buckets and walked away with six buckets of assorted sizes. The one that caught my attention was around 4 gallons (I can't exactly measure it to be sure now). I attacked the bottom of said bucket with my drill. So now I have a 4 gallon with a perforated bottom and a normal 5 gallon bucket
Stack the 4 inside the 5.
Lift the bag and let the draining slow down a bit.
Lower it into the strainer bucket.
And apply some weight.
I usually use a Homer bucket full of bulk grain, but today the mill had to fill in.
I'm extracting more wort than I was by squeezing by hand, and I"m not burning myself doing it!
After reading up on BIAB and all the "problems", I found most of the solutions pretty straightforward, such as yours. I used a largish stainless colander and the bag fit well enough, a little slop over the sides.
And it was funny, I had a friend over to help with my first BIAB, and he thought I was improvising all these solutions. I then showed him this website and everything that I did was mentioned here.
Mine is almost identical,(minus the perfectly symetrical drain holes.)HaHa.
I did notch out a rib,close to the top that holds a pc of 3/8 tbing in place.I run this tubing down the side of the bucket and into the lower bucket.This relieves the suction pressure when you pull the two buckets apart.