Cleaning Leather With Household Products
I don't think I would go with windex or pine sol to clean your leather seats. If you don't have a decent leather cleaner and conditioner, use a lightly damp rag (The key is to use as little water as needed) with just a few drops of mild hand soap worked into the rag to clean the leather.
Use firm pressure to wipe down the entire seat. Refresh the rag when it gets dirty, and replace the rag when it can't be rinsed clean. Remember, a LIGHTLY damp rag is what you should be using.
Use a separate rag that is lightly damp to wipe down the leather, to remove any soap. Use a third rag, DRY, to wipe it down one more time. Wait for the leather to be completely dry, then massage olive oil into the leather. About 5 drops on a clean dry rag will go a long ways. Use firm pressure to work the oil into the leather, adding more oil only when you are sure that all of the oil is out of the rag. You don't want to get the leather sopping wet with oil.
When you are all done, the leather should not be shiny, sticky or darker in color. It it is, use another clean, dry rag to buff off the excess oil.
There are special leather cleaners that you can get at your local auto parts store that will do a better job at a real deep cleaning, but you shouldn't need to use it all the time if you clean it good once, and use the above steps on a regular cleaning basis.