Cooking Spray

So, I heard there was a great way to save money by making your own cooking spray.

The first recipe I tried was this:  
1 Part oil
4- 5 parts water

Mix in spray bottle or brush on

I baked banana bread and while both loaves came out easily, I was left with this.

Left was homemade spray

I added more oil to 50/50 put it in a spray bottle instead of brushing it on and baked cupcakes.
I got this:

Can you guess what row had the homemade?  This recipe is all over the internet, or versions of it.  Not sure what I am doing wrong.  For now I'm back to the expensive can of junk. Sad.