“If it doesn’t affect the taste then it’s not a problem. if someone ordering vanilla got some chocolate in it, they’d complain. So the rinsing must be good enough to prevent that. Tell me why that should not be good enough for kashrus purposes.”
And I’m sure every now and then a Baskin Robbins customer does complain that it is a bit off flavor due to an inadvertent mix. And gets a new cone (free) to replace it.
You’re okay with a Jew every now and then getting a little treif flavor?