Salt + Sodium Bicarbonate releasing water in carpet
I've never heard of sodium chloride/sodium bicarbonate being an effective dessicant. Pure sodium chloride is not hygroscopic at all.

However, in air sodium bicarbonate slowly decomposes to sodium carbonate which in fact is hygroscopic. If sodium carbonate, and hygroscopic impurities in table salt, such as magnesium chloride or calcium chloride, deliquesce in air of high humidity to give small droplets then these droplets start to grow due to a high concentration of dissolved salts (including sodium chloride and bicarbonate). The effect is reversible at low humidity or higher temperature.