Yup! That is what I do - I (mix) do them both...
I live in upstate New York and get down 3-5 times a year for usually 10-14 days at a time...and so I hit it pretty hard when I am there (since I can't spread it out like the locals). Usually do only one dive per day, but they tend to be longer and a bit more involved. I was getting ear infections every trip until this - has not happened since. I got to know the symptoms pretty well, and when I get lazy, I can feel one coming on. I do a fair bit of deco and might push the O2 clock a bit. Since Afrin/Sudafed are recognized CNS stimulants (quite effective in the ears though, until rebound kicks in), they are an option I personally feel are not an option. I really like the DM version - in the ear area, it feels alot like Sudafed/Afrin...and I believe from what I read on it, that the DM may act opposite to CNS issues, potentially alot more diver freindly. On occasion, I have stayed at Holiday Inn Express, but maybe someone who is more knowledgable can comment on this?
To Red Hat's question - have not noticed a narcosis difference and for some of the dives I do, that definitely could be an issue (adv mix). I reliably narc at 160ish on air during the working part of a dive...makes bottle drops a bit more fun though. :)
Mucinex tends to keep you drained (and the DM dries me out - similar to the Afrin) and reduces inner ear blockage up the tubes - ear beer evicts the bugs. Repeated and extended exposures to cool water still tends to build up and cause clearing issues for me though - then a day off is in order.

