Has it been through the dryer? That sets a lot of stains and makes them more difficult to remove. Still, I have found that some things will come out after a second or third soaking with Oxyclean. Use hot water to dissolve the oxyclean, then add the shirt. Let it soak overnight or until the water is completely cold. Rinse and repeat if needed. I also find that allowing the fabric to dry before you add it to the oxyclean solution means it soaks up the solution and gets into the fibers better. I would think the oxyclean or an enzyme cleaner would work on a fruit stain, but never had a problem with peaches that I can think of.

Is this juice from a fresh peach, or a bottled peach juice?

A bottled juice could have some artificial coloring in it.

It's a fresh peach and it's been through the dryer multiple times (bad, I know, but I kept hoping it would fade with more washes and my other excuse is I have two 2-year-olds who keep me too busy to deal with stains properly).

But I'm happy to report that another soak with oxy + tide seems to have faded it considerably and sunning helped as well. Now I almost can't see it anymore so one more treatment and maybe it'll be out. From now on the kiddos are eating peaches in dark clothing...

Don't feel bad -- I think the first time I bought Oxyclean I was pleased with how it took out a stain and decided to try it on a quilted Christmas tree skirt that had been washed and packed away for most of a year. The red fabric bled onto the natural fabric next to it. I'm pretty sure it was washed in cold and may have been dried on low -- but in the dryer. It came out. I was stunned.

I know several people who swear by the Tide Stain Pen. I have one but haven't really had the need to try it just yet so I can't attest to it.

A lot of people love OxyClean but that's one product I've never had great luck with for stains.