I don't know about rapid relief but I have a tube of Desitin maximum strength on the vanity ready at a moments notice. I've never seen rapid relief Desitin. Does it actually exist?
It's now called Desitin Daily Defense. Has only ~12% zinc oxide. Cleans up quickly. No smell (?). Haven't tried them. I typically use Equate Diaper rash ointment (Walmart brand) (40% zinc oxide).