Subject: How does adding salt to PSA+water turn the 'slime' back into a liquid?

"Super slurper slime" is made in one of our workshops by adding polysodium 
acrylate to water.  As far as I understand the water molecules get trapped 
in the psa molecule.  We challenge the students to think of substances to 
add to the slime that would turn it back to a liquid, or release the water 
molecules from the psa.  They try salt, alcohol, baking soda, sugar, 
vinegar, soap, flour, pepper etc.  Salt is one of the ones that works, 
however I don't know what is actually happening at the molecular level.  
What chemical properties of salt allow it to do this? What other substances 
would work in a similar way? All salts?

Re: How does adding salt to PSA+water turn the 'slime' back into a liquid?