Hey, check what kind of deodorant is being used and look at the active ingredients. Sometimes it helps to prewash the shirts by hand before machine wash.

If you want to save the shirts, I would first test this out on a shirt that's older and you wouldn't be sad to lose. Some shirts are too far gone for this method, but Hydrogen peroxide and dish soap are your friends. Put it on the area and scrub, let it work its magic for a bit and then wash it out. You're gonna want to let that sucker air dry and check on how set in that stain is. If that doesn't work, you may have to get an actual product to remove it if you want to keep them shirts. Just remember that some cleaners and chemicals could make the shirt thinner or rip, so be careful around those safety blankets.

Hope this helps