You can use alcohol, or anything that will clean brass/ss. 
I use a compound called Simichrome to clean the connectors.
It leaves a slight film which inhibits oxidation.
	
		
			
		
		
	
			
			I use a compound called Simichrome to clean the connectors.
It leaves a slight film which inhibits oxidation.
 
				
		 
 
		 
	
 
 
		 
	 
	 
	 
	 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		