Don't beat yourself up, sometime we can't help it and just follow the urge to buy/try something new. I consider it as a part of the never ending learning process.
Sochting Oxydator is definitely 100% safe, it won't kill any livestock and produces just water and pure oxygen. The secret is in the ceramic ring/bowl, it contains magic dust (I accidentally broke mine and it is full of black stuff, carbon I suppose) which breaks down molecules of hydrogen peroxide. If you want to extend the refilling period, you can use just a half of the catalyst. Obviously it will also limit the amount of oxygen produced, so..choose your poison I guess