Similar effect in the gas phase?
If the intent is for a solute to disolve fines and salts this wouldn't work so well but if not, why not use hydrogen? (taking care to prevent mixing with near equal proportions of molecular oxygen)
If the chemical activity is due to oxidizing reactive species, would it be feasable to flush the lock with molecular hydrogen at a pressure such that assuming there would be a (neutralizing trended) chemical reaction, the heat wouldn't cause damage.
Then a blast of CO2 in your gas shower, evacuate the H2 and settle in for a nice cup of tea.