I'll copy two sections from a site that talks about salt. I'll also include the link so I hope this gives proper credit to the author. I think the part I put in bold specifically addresses your question. I personally believe it is better to try to keep salty stuff away from them since it is easy to give them too much and they normally get enough naturally. All our set-ups and practices are different however, so you have to decide for yourself.
Animals have an innate desire to consume salt. Feeding a salt-deficient diet will lead to increased
feather pecking and a decline in egg production. Most animal feeds will contain added salt, usually in the form of sodium chloride. Iodine is rarely added as a separate ingredient. Instead, iodized salt is routinely used. Cobaltiodized salt is often used
in diets for swine and ruminants, and this can also be used without any problems for poultry. This type of
salt is usually blue.
Sodium is an essential nutrient, playing a major role in maintaining body fluid volume, blood pH, and proper osmotic relationships. A continuously low intake of salt can cause a loss of appetite. Sodium deficiencies adversely affect utilization of dietary
protein and energy,and interfere with reproductive performance.
Chlorine is also an essential nutrient. Hydrogen chloride (HCl) released from the true stomach (proventriculus) is important in digestion. Chlorine also plays a role in maintaining osmotic balance in body fluids. Birds deficient in chlorine are more nervous, showing increased sensitivity to sudden noise.
Although the salt requirement of birds is relatively low, adequate levels are essential, and excessive amounts are highly toxic and reduce egg production. Birds require a sensitive balance between necessary and toxic levels of salt. SeeTable 1.
Excess dietary salt intake readily causes wet droppings and wet litter. Several feed ingredients,such as fish meal, corn gluten meal, meat meal, whey and sunflower meal contain high levels of sodium. When such ingredients are used, the level of supplemental salt (NaCl) in the diet must be reduced.