Shelley - learn from my mistakes. I tried to make Rejuvelac several times, but each time it was really smelley - putrefactive bacteria. I covered it and took all precautions even adding salt & lactofermented whey, but it didn't help much.
Then I found out why - basically most store bought cabbage is "dead" - it has no live bacteria on it. So when you ferment it, all you do is putrefy it.
So my advice is to get some really fresh cabbage - preferably hand picked.