Michael,

The sunlight induced photooxidation, used as a water treatment approach, can be enhanced by adding some lime juice or fig juice.  Limes, figs, celery all contain psoralens. 

We use a wood ash solution to decontaminated our wheat straw prior to its use to grow oyster mushrooms.

Getting a pH below 4, using lactic acid producing microbes or above 10 using wood ash can inhibit the growth of microbes.

my 2 cents,

Mike