I tried using a manufacturers coupon from a very well known US company (Raid Roach Spray) in 2 well-known US stores (Home Depot and?

Do not go to these sites. They will steal your credit card information.

WalMart always accepts paper coupons

Home Depot never has accepted anything but in store coupons

I DON'T BELIEVE YOU.

The cashiers are BS-ing you. Both Walmart and Home Depot take manufacturers coupons.

Were they expired?

The cicadas used to be really bad around here in the summer, and they would make a bunch of noise while I was trying to sleep. I bought this stuff from Raid, I think it was for wasps, it would shoot really far. I would use my hearing to find them (they would usually be in cracks and corners), spray where they were, and step on them. I never used a coupon though, I would just buy it.

You can try contacting the manufacturer and see if they will send you the free product.

Or you can try a different chain.

Many large discount chains will not accept coupons because they have to pay a percentage.

You have to take them to a store that accepts coupons. Costco and Sam's don't accept coupons either.

Walmart accepts paper coupons not smartphone/electronic coupons.

HD only accepts their in-house coupons.

The policies are on their websites.

If you want to use the coupon check other stores.

It's got lots of chemicals

You can't really do anything about it they have the right to choose the form of payment. But before going in next time call ahead of time and ask if they accept the coupons so you don't waste your time on a worthless trip.