What can I do to remove the old stains out of the wood, the house was built in 1955???

we are refinishing our floors Janine and we have rented the floor sander from home depot and we had a few stains in our wood too some were water and some were from the carpet and pets. Anyways we used the product out at dollar general called clorox oxy magic its in a spray bottle we applyed it to a Q tip and rubed it on the stains and let it dry it took it right out. we have oak floors and im sure it will work on all wood types give it a try if you want and see if it works for you.

Thanks!! I'll give it a try.