using ln2 would help cool the switches so you don't end up melting them by mistake also. clne and ln2 bordered by dmnd to contain the ln2 around the switches generally is effective.
i assume your problem is that the spark doesn't stop when you want it to. i would suggest that you put a little more space between the switches so that you don't have sparks jumping between the switches. that helps. and to get rid of unwanted sparks in other parts of the save press ctrl =. it might take a try or two but it usually works. you could also try putting some kind of non conductive insulation between the switched instead but more spacing would be more effective. hope that helps :)
One doesn't need to cool down metal, it won't melt on its own accord... Also, the water is what's causing the electric loop. Use distilled water instead)
hope that all helps.