What the hell is with the panic attack guys? The tank regulator only OUTPUTS air, so how is oil going to get in it? The only way oil can get into a tank is through the fill nipple which isn't anywhere near the ASA. At 3000 or 45000psi the pressure is likely to make the tank blow up if you get it in there, but if you get lube in your gun that 850psi is not enough to do anything. So it's fine to put a little bit of oil on your reg threads just to make it easier to get it off the ASA, just don't get it near the fill nipple and get a nipple cover if you don't have one already.
Of course, it would be better if you invest in an ON/OFF ASA then you can just ease off the pressure and the tank will come off like butter. If you do use a lubricant on your threads be careful to use only a tiny amount because some guns don't like it when oil gets in their internals, your manual or the internet should tell you wether this is the case. Theres even a couple of guns (angels?) that you relube by putting oil in the ASA then dry firing. Again, your manual or the internet will tell you this.
I would still advise that if you don't feel comfortable doing something then don't. Treat everything in paintball with the utmost respect and our near perfect safety record will be maintained.
Heres a source:
http://www.youtube.com/user/paintballtechpb#p/search/0/L6IA5mGelR4
Once my Sp1 was aired up, it was extremely difficult to get the tank off so I bought a SmartParts ON/OFF ASA . But it turned out to not be a true ON/OFF at all as it didn't bleed the air out of the ASA. At the time I didn't know how truly crap SmartParts ASAs were. So, I had to carry on putting a small amount of lube on the tanks THREADS just to make it screw in an out a little easier. To be honest I was probably a bit too generous with the lube, but it's never affected my Sp1's performance and it still shoots today. Also, my tank has never exploded as I never let the lube got anywhere near the fill nipple.