Hey! My guide!
Rule of thumb, don't use 99% of silicone lube you can find at Canadian Tire etc. It often contains solvents which will destroy your o-rings.
RC Cars/Plane shops sell shock weight oil which is pure, but way too thick to put in magazines, but is ok for silicone used in lubricating the gun.
Airsoft stores should, realistically, be the only place you should buy silicone oil.
Ultra Slick (the one Hectic posted) is absolute gold for lubricating GBB mechanics.
Ár skal rísa, sá er annars vill
fé eða fjör hafa. Sjaldan liggjandi úlfur
lær um getur né sofandi maður sigur.