Let's see the reaction for each situation.
2 NaCl + C₂O₄²⁻ → Na₂C₂O₄ + Cl₂
CaCl₂+ C₂O₄²⁻ → CaC₂O₄ + Cl₂
Thus, it would differ whether the main product is sodium oxalate or calcium oxalate. In their solid forms, both are white. However, calcium oxalate is insoluble in water, while sodium oxalate is slightly soluble. So, if you used NaCl instead of CaCl₂, you wouldn't observe any precipitate in your solution. If there is, it would only be minute.
