Witches brew is electrolysis,
1. one 55 gallon plastic barrel
2. 1/2" rebar welded in a grid patern
3. one non-electronic battery charger (I use 40 amps)
4. arm & hammer washing (powder) detergent.
5. water to cover all items
Mix the soap into the water make sure it is dissolved.
hang rebar off of side of barrel (I use two on each side of the barrel), suspend the items for rust removal between the rebar (not touching) connect the positive to the rebar and negative to the items for rust removal. turn on charger and let the items brew for a few hours.
The items you are doing will begin to bubble and that is the electrolysis eating away the rust the bars with the positive connected to them will collect the particals from the items being conditioned.
I have used a small baby pool and completely de-rusted my windshield one side at a time.
Caution: the bubbels are hydrogen gas (no smoking)

There are great vids on youtube for this, start with a 5 gallon bucket first and work your way up to big tanks
If I had a bigger tank I would put the frame or tub in it and not use a sandblaster at all just wire wheel after use.
work smarter not harder