What do we use when we run our silencer wet?

We like to shoot our cans "wet" from time to time to show what the difference is between dry and wet operation and the material we like to use most often is either Hoppes #9 or simply some common gun oil, these will usually smoke a little but the gun will not rust from these liquids. Alternatively we have also used water, but this necessitates cleaning promptly after the range session so that the host weapon doesnt rust.