We used to sell poop slimes when I worked at a dollar store. We also had "unicorn poop" which was colored marshmallow candy shaped like a poop emoji. I swear kids are gonna have scat fetishes when they grow up.
I'll push back against that last point for one particular reason. Children are by definition immature and are very often fascinated with gross things.
Poop is included in this fascination. It's usually driven into kids at a very young age that they should not play with poop, and adults find poop disgusting enough that the kids learn not to talk about poop around adults. But they still talk about butts, farts, poops, toilets, diapers, sticky things, slimy things, stinky things, dead rats, creepy crawlies, killing Barney, and so on to each other all the time as long as they think the grown-ups aren't listening and/or aren't about to shut them up. Kids are generally gross. Juvenile humor is, in a word, juvenile.
The natural progression of things is for kids to grow out of this. Poop stops being funny, as does everything else that kids giggle wildly about behind adults' backs. Girls stop having cooties too, and so forth. It's normal.
Granted, I'm talking about the ideal scenario. The non-ideal scenario is that kids grow into adults who still find poop funny, and thus become the scourge of public restrooms nationwide. The extremely non-ideal scenario is that these kids grow into adults who find poop to be sexy, and thus become furries. These people will always exist, due to how evolution and natural selection works.
(Pedophiles will always exist for the same reason, which makes them no less abhorrent -- remember, even Jesus said that kiddie-fiddlers should be weighted down with rocks and sunk in the sea.)
So when I see companies selling lolpoopie stuff to kids, I don't worry
too terribly much. Dumb marketers are dumb marketers.