Not sure if this is 100% scientifically backed but I read a bit by a dental hygienist on a forum that you shouldn’t rinse when brushing with proper toothpaste because it can help remineralize the teeth if when its not rinsed away after
Its annoying but its a good way to cut down on mindless snacking at the very least for me so its something I do sometimes. Hope its not voodoo
It’s the foaming agent toothpastes typically use (sodium laureth sulphate - SLS) suppresses the sweet receptors on our tongues.
When you drink OJ right after, the sweetness is suppressed and you only taste the bitter and other flavors.
Edit: SLS also breaks up lipids that may be blocking bitter taste receptors on your tongue.