We did lots of similar things in WWII, also in Vietnam.
Sometimes they work well.
It is always difficult to measure the effects.
It depends on the morale and dedication/fanaticism of the forces. The Russians comprise of conscripts who are abused, demoralized, poorly equipped, and often hungry. If they are convinced that surrendering will mean food, shelter, fair treatment, and eventually a chance to go home, I believe many will take it (if they aren’t murdered by their NCOs and officers for attempting to surrender.)