I've read the wiki and about 12 pages of posts and didn't see my question - only the 'reverse' of my question. Forgive me if it's been answered.

I arrive into the domestic terminal and depart 12 hours later from the international terminal T5. I plan to spend the day in the city and then come back for my flight. I have access to the AA Flagship Lounge. If I leave the airport and then come back, will I be able to access the domestic terminal/T3 to access the flaghship lounge based on my international departure boarding pass? I'd like to take a shower.

I know that if so, I'd have to leave T3, take the train, and re-clear security to T5 after the lounge visit. But I just need to know if I'd be allowed to go to T3. Thank you!