Does ethanol destroy RNase?
I think the protocols to clean glassware take no chances and just care about RNA degradation rather than targeting one class of enzymes.  

EtOH is supposed to denature RNAse and any other proteins on the surface.  

Other chemicals such as Diethylpyrocarbonate  (DEPC) used to wash glassware kill all biochemical activity by reacting with nucleophilic moieties in the protein (-OH, -SH -NH(2/3) ).   (See comments below for more.)

These treatments are followed by heating at 300-450 F for 2-4 hours.  This is not a specific RNAse decontamination - all biological activity is killed. 

RNAse activity is not assessed by specific detection of a particular enzyme, but rather judged by the degradation of an RNA sample in the lab environment.  So specific inhibition isn't worthwhile - any protein that might interact with and degrade RNA is called an RNAse in these protocols.