Any thoughts on if its ok to add boiling water to a keg in order to thoroughly sanitize? I had a batch of blonde ale somehow get contaminated and now I really want to make sure there isn’t anything in that keg that could spoil another batch. Actually, now that I think about it, how about running that same boiling water through the beer line? I doubt the vinyl tubing is rating for liquid that hot, but thought I’d ask.
Not a good idea, especially for the tubing. Boiling water will kill germs, but only after 5-10 minutes. There’s no way you can keep water in a keg boiling long enough to sanitize it, and boiling water is an even worse idea for tubing. Break your keg down completely, soak all the parts in Starsan or iodophor and throw the tubing away. Then put a gallon of the Starsan into the cleaned keg and push it through the new tubing and faucet.
+10. What is your procedure merrickne? Line is cheap. If your line is just dirty run some oxyclean through for the short term and replace. The oxyclean works miracles. A dirty beer line can make a beer taste unpleasant.
I use oxyclean to clean my kegs and has worked very well so far (I’ve only been kegging for bout 6 months). I just really wanted to make sure I killed anything living in there. Guess I’ll stop being overly-paranoid now 
When I clean a line it takes about 30 minutes. About 2 qt of hot water and a couple Tbs of oxyclean. Shake well. Pressure on the keg (couple psi) to get things moving. Drain the keg slowly- about a cup at a time.