From: tallorder64 

I am now retired, but I used to own a commercial cleaning company.  
All of the commercial cleaners that I know use this formula for 
spray cleaning.  Even Consumer Reports rates this cleaner as good or 
better than store boughts.

In a one gallon container put the following:
2 cups of sudsy ammonia
1 pint of rubbing alcohol
1 capfull of dishwashing detergent

Add water to fill container and put in a spray bottle and use.  Keep 
gallon container capped to keep alcohol from evaporating.