7-11's started a program where you can have stuff shipped to them for a fee. Then all you would have to look out for is a police car in the parking lot.
I know for a fact I could have anything mailed to half-a-dozen Durk-a-marts.
Tonight, for example, I walked into a Hajib-fest. One dude is probably about your age, has a beard halfway down to his balls. He, and three of his cohorts were chattering in Pak, or Farsi, or god-knows what.
They sell crack roses, scales, brass brillo, dick pills, counterfeit batteries, glass weed pipes out the ass - pretty much anything. One extra box from a sketchy location probably doesn't matter, they must get sketch shit alla time.
Most of that shit comes in bulk, the UPS motherfucker just wheels in a handtruck of shit from China. I wouldn't be surprised if they had yellowcake uranium and dynamite vests in the back room.
In your case, it might not fly. Nothing personal, but they probably dislike "your kind". Its all about being pals, regular customers, friendly, and not ripping their balls on the prices of common store goods. They like having a "crew" of regulars, who come in and out, and serve to be the basic protectorate of a struggling business. Because people come in there and treat them like shit on a regular basis.
If you work up that camaraderie, you can get a package sent there. They'd be happy to do it for ya, for a few bucks.
I'd rather have something illicit sent there, than a Mailboxes, Etc location. Those cunts will rat you out in a minute. In a MBE or UPS Store, you have to show ID to open a PO box. They normally don't just take "general delivery".
I actually used to have a "General Delivery" address at a rural PO location. This was in the days before sand people blew up the twin towers. I'm pretty sure the General Delivery addresses are super rare nowadays. Maybe in DirtRoad, Oklahoma, you could find one.