My children attempted this experiment last weekend, and I made them walk me through their process.
Purpose: To see if rust would pull off the axle with electrolysis.
Materials: water, baking soda, steel rods, clamps, bucket, battery charger, wires
Observations: Water bubbled. Rods began to attract rust. Water filled with rust. Could see the portion of the axle in the water being cleaned.
Conclusion: Removed some rust, but not all.
Factors That Could Be Changed for More Success: Submerge axle fully. Use more baking soda. Use more wire and rods. Use higher battery charge.
[The left side is the side that was submerged because it is lighter in color and more recently exposed to oxygen. You are seeing the sub-layers of rust that haven't been exposed to oxygen in many years.]