To bring things back to center - guillotine.
Perhaps we should limit the products to exclude things that have their own designation but form a subset with a proper name - which would accept Macadam the paving material but disallow Macadamia nuts, since there are plenty of nuts of other sorts.
Lots of physical constants were named for people, too: ampere, ohm, volt, watt and such are so much part of the language that they don't even get capitalized any more, and many elements (especially the newer ones) have people's names too. But of course they aren't products, strictly speaking. Or even loosely.
And don't forget that a lot of names came from things, rather than the other way around. I G Farber, for example, likely has someone back in the past being a merchant working with colors, etc; Steins, Woods, Coopers, Millers, even Smiths all have names with identifiable origins. Though there's always the possibility that some names were assigned arbitrarily at immigration centers...
