I mean, yes I know how to rinse it away but it spreads around so much and looks so bad if left (not to mention staining) that you have to be quite meticulous, scrutinising the disaster zone and rinsing rogue grains out of corners.
That is a slight pain in the arse. It’s not the mindset I especially want to be in when doing something that’s meant to be a little bit indulgent and relaxing.
Just easier overall to use a scrub that doesn’t make a mess.
(I also really hate the faux-cheeky, chummy, “saucy” packaging of the Frank brand but that’s a separate issue)