Phil struggles with a gallon of milk. He makes his wife *thumbs toward door* bring all the heavy shit in (horses are good working animals). I honestly cannot imagine him doing anything other than either checking Costco membership cards when they walk in and press the button on the counter thing (I'm pressing buttons!) or checking receipts when people leave. He'd still manage to fuck that up, even though that'd be a decent gig for someone who has no marketable skills beyond being an extra in The Walking Dead with minimal makeup.
Wal-Mart used to hire old people as greeters. He COULD do that, cause he could sit in a chair on a donut (muh back injury) and just say "Hi, welcome to Wal-Mart!" as people walked in.
But, his overall disdain for that store, it would probably be more like: "Um, *snort* *lip smack, head shake* welcome to uh walmart?" and as the customer walks past, he'd mutter under his breath "What a bunch of empty headed fucks...." and get fired in the first 30 minutes.
If there's a short event that happens between cheersandsubs payments, he wont have the money to pull his pud to pecs and packages. So, he needs tho that money, he really does.