Is It Safe to Leave Star San in My Keg and Beer Lines?

I couldn't take it anymore. After trolling various forums and listening to podcasts, I couldn't get a clear answer to this question. So I called up Five Star Chemicals (makers of Star San), and was immediately connected to a tech to answer my question (wish I got the guy's name so I can thank him here).

What I got out of it was the "ideal" way to clean and store kegs (and lines), based on what Five Star has heard from the various keg dealers that they've worked with. Here goes:

The Procedure for Cleaning Your Cornies and Beer Line

1. Clean the keg as soon as you can. Rinse it and the lines out with water (for all line-rinsing steps, I pressurize and use the keg, run through the lines and into a bucket or something). Then, fill the keg with warm to hot water, add in the proper dose of PBW, and clean away (I reserve a clean, never used on anything else toiler scrubber for this, and a thin, long-handled dip tube brush). After some initial scrubbing, I let it soak for at least 20 minutes or so. I also take the keg posts, the black bev-out connector, and the lid, and soak them in a separate solution of PBW. I then dismantle the faucet, and let it soak in there too.
2. After the keg has soaked, I give it another quick scub in case there was some grime that the PBW loosened up. Rinse and put the faucet back together, and rinse and put the black bev connector back on the line (quick disconnect models are a life saver here). Then I dump all the PBW from the keg except for a gallon or two, hook up the keg to the lines, and start to run the solution through the beverage line. I stop at some point, so the PBW can sit in there and dissolve any gook that's stuck in the line. Since PWB is a CIP (clean in place) cleaner, it's designed for this sort of thing.
3. Rinse the keg with warm/hot water. Believe it or not, you should rinse with the same temperature water your PBW was in. For some chemical reason, it rinses better this way as it won't "scale" (a typical issue with hard water).
   
4. When the keg is rinsed out, fill it with a gallon or two of water and run some through your lines to rinse the PBW out.
5. Time to sanitize! Rinse and reassemble all keg parts. The ratio is 1oz of Star San in 5 gallons warm water (not too hot, like over 120F - typical hot water heaters are around 130F). However, I cut this in half. Put 2.5 gallons in the keg, then add the .5oz of Star San (always important to add chemicals to water, not the other way around). If you want it to foam, put some of the water in, then add the StarSan, and then pour the rest of the water in. 
6. Seal up the keg, and shake it up. (Don't be surprised if some leaks out the lid, as the lid requires some internal pressure to get an air-tight seal - watch any carpeting here, I always use a towel on a non-carpeted floor). Let it sit a few minutes, maybe turn it over and/or let it sit on it's side for awhile (Star San actually only needs 30 seconds). From here, you have a couple options:
   
   
   
   1. Hook up the keg to the lines, and run all of the Star San through the bev line. Run it all through because you don't want any left in the keg or the line other than what's clinging to the sides. Do not rinse. Stainless steel should be stored with some sort of acid coating, as it helps it maintain its "stainless" state. As an acid sanitizer, Star San works great for this. Besides, if you rinse after sanitizing, then you're just ruined all that work - that's why we choose no-rinse sanitizers. As long as you mixed/measured properly, you won't have any problems (and the measuring device on the Star San bottle makes this brainless). When you're ready to fill the keg, just open up and rack the beer in and proceed as normal. When ready to serve, hook up the bev line, run a half glass or so through, discard, and you're good. Or (and this is where I was most surprised)...
      
   2. Dump the Star San, and pressurize the keg to seal it up. When you're ready to fill, mix up some more Star San, dump it in the keg, let it sanitize again, run it though the lines, and then fill with beer. If you're the paranoid sort (and you know who you are), and it's been awhile since you've originally sanitized, then this will neutralize anything that may have gotten into the keg/line. Since Star San doesn't sanitize indefinitely, it will loose this ability over time. So bottom line, if it's only been a week, you're fine. Any longer, and you want to be extra extra sure, follow step 'b' here.
7. Relax and have a brew.
   

Now, this is the recommended way of doing things with Five Star Chemicals. (Actually, Five Star has products specifically for cleaning/sanitizing line cleaning - but I didn't go into that here.) Some guys use Oxiclean instead of PBW - I do this for some stuff. But it's important to realize the Oxiclean is not a CIP cleaner. Oxiclean is also missing a "surfactant" - which basically breaks down surface tension in water, which allows it to penetrate and dissolve all those nasty organic compounds in either hot or cold water. In short, PBW is designed for brewing equipment, not laundry. So for line cleaning, PBW is certainly better, and actually allows you to be lazier by letting the soak do most of the work.

Now, if you have your own way of doing things and it works, that's great. As with anything related to homebrewing, there are many ways to do the same thing. Cheers folks.

Update August 10, 2010:
I've since modified my line cleaning - I got one of those hand/line pumps and use BLC instead of PBW on the lines. I rinse with warm water, then BLC - letting it sit and recirculate. Then rinse again, and then run some StarSan through it, also with the hand pump. I just felt like I was wasting a lot of CO2, and the hand pump is quick and easy. I don't bother pressurizing the kegs for storage anymore, since I sanitize everything again just before I use it. Also, I take the liquid-out fittings apart now and soak them in PBW.