I tried electrolytic cleaning last night, overnight. but it didn't work

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- Plastic bucket, washing soda and sacrificial anode (broken garden fork) clamped to side.
- Soda bucket anode.jpg (54.38 KiB) Viewed 9326 times
I used:
- The prongs from a broken gardening fork (not vintage) as the sacrificial anode (red/+ve side) in a plastic bucket.
- I used
Washing Soda (before reading Nic's warning, above) - or at least the closest thing I could find to it:
Dri-pak "Soda Crystals", "...contains sodium carbonate decahydrate greater than 30%"* dissolved in tap water for the electrolyte.
- I used my trusty(?) old homemade battery charger (1A trickle charge, half cycle rectified).
When I set it up at first I saw bubbles rising from the cathode (black/-ve side) - looked promising. When I check back an hour later - no more bubbles.
Another hour later, no bubbles & I rotated the tool. This morning, no bubbles and no real sign of progress.

- Electrolytic cleaning rig with old, homemade battery charger (transformer + 1 diode). Anode dry, rusty cathode clip in electrolyte.
- Electrolysis rig.jpg (52.5 KiB) Viewed 9326 times
Like Gavin, I am unsure what is wrong. However, unlike Gavin, my old battery charger has no fancy electronics, it is just a transformer & a single diode rectifier.
Some other possible factors that occur to me:
1. It was really cold last night. It looks like some of the crystals may have come out of solution as a result.
I tried adding some warm water first thing this morning to warm it up & help saturate the crystals, no improvement though.
2. Water round here is hard. It is likely that the washing soda reacted with the dissolved chalk - that's why we use it normally.
Could this be rendering the electrolyte useless/weak? I tried adding more soda crystals but no visible improvement (i.e. no bubbles).
I was thinking perhaps my 1amp trickle charger might not be up to the task but then came across this excellent article and this chap is
using a very similar setup, 1.5amp slow charger and washing soda, to good effect:
http://www.instructables.com/id/Electro ... aka-Magic/*For comparison, Arm & Hammer Washing Soda (.used by our American friends) appears to have considerably more sodium carbonate in it.
Ingredients from MSDS/Label: Sodium carbonate ~ 85%, Water ~ 15%