MY experience (several years worth) suggests two things:
1) There IS no "substitute" for Super Dri. There are dozens of alternatives (Transmission fluid seems to be the most popular) but each, imo, sacrifices SOMETHING. Either it is more difficult to ignite, produces less smoke, thinner smoke, harmful (to the airplane or potentially even you) smoke, etc. Every alternative I've seen sacrifices SOMETHING to super dry.
2) If you're going though 32 oz in 5 minutes you are running WAY WAY WAY WAY too high a volume. I regularly get _2_ 8-10 minute flights out of a 32 oz tank in a twin. I believe your "solution" lies not in finding an alternative mixture, but in significantly limiting the amount of oil you're currently using.
Depending upon your smoke pump, you may be able to simply mix it down to a lower speed, or electronically limit the voltage, or mechanically limit the intake side of the oil lines. (I always shy away from limiting the out put side...it drives pump current up considerably, shortening battery life)