You never used OpenDime ? https://opendime.com/

open dimes offline.cash fedimint

all these enable this

This isn't a dumb idea. It's just unclear how it would work offchain for small amounts.

I guess you could use something like an open dime (if it were cheaper) and (if you're a business) batch many of them at once onchain.

That's literally what the first ever physical Bitcoin coins, Casascius, were.

You can move them around and whoever holds them has the private keys.

You can scan the address with your phone and verify the amount is still there.

There are many other projects that work like this as well, plenty use lightning as well for smaller amounts.

It's possible to do transactions via other networks than the Internet. For example, in Africa there is a service that operates over the cell networks on dumb phones.

Just buy yourself a sats card and try it out

I'd guess it's easier for a local mint to cover the area with wifi access spots even if the access only reaches the mint itself, not the wider internet.

There's also a possibility to do one-sided LN channel that can't be closed before a certain date. Such a channel could be used fully offline, but of course to route payments you'd need at least a local network.

That's LN. They come in two halves that each side update concurrently. They are offchain. All you need is an LN node and the channel key.