No, I haven't tried bleach, I don't like the smell of bleach either. Bleach won't ruin a thick fleece pad? When I bought it I thought I was told to not use bleach? I could be wrong though.
If you use bleach make sure you out it through a extra rinse cycle that smell is hard to get rid of and it can also irritate the pups skin. We use white vinegar, let it soak rinse and then use regular detergent .
I love bleach. I buy it by the case. I always use it to wash puppy pads, even if they say not to. I do use the "extra rinse" cycle for puppies though. I wish i could use bleach on my darks, too. Love it.
You might try Baking Soda and do an extra rinse. I use bleach and sometimes soda. They have some Bleach that are scented and rinse once or twice to make sure they are clean.
I throw Simple Solution into my washer. I don't have pups but I use it whenever I wash the dog bedding and towels and the like. I put maybe 1/4 cup into the detergent container with the detergent and about the same into the softener container of the tray.
I use bleach too, but I also use liquid fabric softener. I'm addicted to the smell of either Downy or Gain Apple Mango Tango. My fleece holds up just fine - I've used bleach for years, plus it kills germs.