G'day Widget apparently it's used as an electrolyte so shouldn't make any real difference. I have used bi carb and believe it's pretty much all the same. Even the quantity doesn't seem too critical. I read you could use plain salt but it's a little counter productive. Just remember to only ever put steel in there. Again I have read that if you use galvanised it releases the zinc and stainless releases chromium both of which are heavy metals and not very friendly whereas using plain steel releases bugger all and can be tipped out without leaving nasties. As coper is not ideal in there I used concreters tie wire as I find rolls lying around on construction sites so can use it once or twice and then replace it. Apparently the smart battery chargers don't work because they sense the load where as an old battery charger or power supply works fine. They say that too high a power and it will pit the surface more and you could even use a spare car battery then recharge when done.
