FWIW: I have reverse block, in one ear only. Started years ago, and is intermittent. It manifests itself as discomfort appearing at depth of ~ 7-8 feet on ascent. I usually hang out at that depth for a minute or two until it clears. However, when I am instructing, and am with a group of students, that situation is 'inconvenient'.
I therefore take Sudafed before diving, on advice of my ENT physician (also a diver). It works. If I don't / forget to take it, I have a 50-50 chance of RB. When I do take it, I have not had any episodes of RB.
(Also, FWIW, I take pseudoephedrine, NOT Sudafed PE (phenylephrine). PE is pharmacologically weak, bordering on functionally inert.