Swag is typically given out for free at events and has company logos etc on it. People like to brag about the free swag they got at a conference.

No one ever really expects to pay for swag in my experience over a decade of attending conferences and collecting it.

I think if you intend to sell it and donate proceeds to charity I would go with company merchandise and just make it clear where the proceeds are going.

And have a pyrogenesis company merchandise store link on the website or something. A Shopify page etc.

Maybe down the line a competition for designs for something small that can be 3d printed with pyr powders and bought on the store. Although I have no idea if that's viable or would have to cost $200 for a keychain type thing. Just an idea