Gah, that's like using a loaf of bread to shelter from the rain (I don't know ehere that analogy came from, I am tired, ok?
) While a regulator may prevent liquid from entering the gun itself, regulators dislike liquid CO2 even more than the gun does. They have o-rings that freeze and bits to leak from as well. A regulator is
not a replacement for an expansion chamber. But an anti-siphon tube deals with the problem well enough most of the time.