This winter, I stumbled on a way to easily remove salt from urine before using it as fertilizer for the garden.
Just put the container of urine in a refrigerator overnight. The salt precipitates out and sticks to the walls of the container. You can then pour out the liquid and the salt will stay stuck to the walls.
I use a wide mouth, roughly 12 cup plastic container (the type used for protein supplements from Trader Joe's). After pouring out the liquid, I've needed to scrub the inside of the container using a rubber glove and dedicated course sponge in order to remove the salt. Tried just pouring in hot water to dissolve the salt. After letting it sit overnight outside in the cold, the salt had not dissolved. Will try letting it sit inside to see if I can get rid of the salt without scrubbing.
Only done this a few times so far. You can really tell if you've been eating salty food, like nachos, by the amount of salt that precipitates. Most times for me it is very little, so this extra effort probably isn't that worthwhile.
Do plan on evaporating some urine after this cold treatment to see if it gets most of the salt out.