Not the writer of this information.
Don't bother! Salt will not do much to help with the whitespot and it may hurt the Corydoras (although C.paleatus is about the toughest species and the least likely to come to any harm). Corydoras are sensitive to not only salt, but also medications such as malachite green, which is in most whitespot medication, so be very careful! On the other hand, Corydoras are not very sensitive to whitespot and are unlikely to be affected - I have never seen a Corydoras with whitespot (which is not to say it could never happen). If this were me, I would move any Corydoras to another tank while treating for whitespot. The parasites which cause whitespot (Ichtyopthirius) are almost always present in aquaria. Fish are only affected by the disease when they are heavily stressed, so the cure for whitespot is to prevent infection by reducing stress! This might be metabolic stress caused by poor water quality (the commonest reason for outbreaks of whitespot is new tank syndrome), overcrowding, poor diet, bullying, or other underlying illness such as tumours, etc. Keep your water and your fish in good condition and you will not get whitespot. If you want more info, read this.
