Help with "sour mash" extract Berliner Weisse

Before everyone yells at me I know that there is no actual mashing involved with an extract batch, now that that is out of the way here is my idea that I'm looking for a little help with. I'm looking for a nice, tart, refreshing beer that will be ready fairly quickly, so I figured I could do a sour mash Berliner Weisse. The only problem is Due to space and equipment constraints I can only currently do partial boil extract batches so here is the recipe I came up with, let me know what you think:

5 gal batch
3 lbs breiss wheat dme
1 lb breiss Pilsen dme
A handful of base grains
1 oz whole leaf German hallertau 15 min
Wyeast 1007

Process:
Collect 3 gallons of water, heat it up enough to dissolve the dme, remove from heat and let cool to 110, throw in handful of base malt in a muslin bag, flush with co2 and float sanitized plastic wrap on the surface to keep out oxygen, and put lid on kettle. Store in oven with light on to try and keep it in the 100-110 range for 24-36 hours. Remove from oven, remove plastic and grains, add hops, boil for 15 minutes, cool, top off to 5 gal, 2 weeks primary and then keg.

 

Boil to kill off the lacto and other wild critters. I not only want a quick sour, but also one that wont purposefully introduce bugs into my fermenting equipment.