Bob, some more math for ya:
2:1 ratio, with the existing 44t sprocket, would require a 22t cog.
Which is cheaper: a 36t sprocket plus an 18t cog? or just a 22t cog?
More math: if they're sitting at 57.2" now, would the 52" be low enough?
Of course, cheapest move would be a 36t front sprocket with the existing 20t cog: 46.8" for $6. Similar would be using the existing 44t front sprocket with a 23t nexus cog: 49.7" for $6, toss another $5 for a new chain, b/c you might need it plus it may be time for one...
I can't help but think that an adult cruiser with a 36t front sprocket looks odd, especially when there's a big chainguard lookin' empty with a lilliputian chainwheel in it.... but that's just my opinion.