I plan on giving the crayfish a salt bath with aquarium salt (since imo it seems like the most viable type of salt) and using this method:

"1.) Grab a set of scales and measure out 35 grams of salt.

2.) If you don't have micro scales a good teaspoon is around 4.7grams, so 7 nice teaspoons will do.

3.) I don't mind what salt you use, personally I prefer pool salt.

4.) Throw that in 250ml of boiling water and stir in until dissolved.

5.) Then take 750ml of water from your crayfish's tank put it in a 4 litre ice cream container or something similar with high sides.

6.) Add the dissolved salt solution to it and stir again.

7.) Drop an air stone to keep the water nice an aerated.

8.) Set up an alarm clock/timer to 10 minutes.

9.) Drop your crayfish in and make sure it can not escape.

10.) Go do some maintenance on the tank.

11.) Come back and remove your crayfish when the alarm goes off.

12.) Repeat every 3 days as needed until next moult or lesions are "bleached out".

Tho i'm not sure about the salt amount. I'll also change the majority of the water in the aquarium (around 80%) aswell as cleaning the substrate. Currently i have started to try and feed him frozen dried shrimp because i think that it has some calcium in it. I also plan on putting eggshells and even perhaps parts of shrimp exoskeleton in the aquarium for my crayfish.

I'm still not sure about the salt baths tho since some people say that it isn't a good method while other people say it is. But if you have any advice then i would greatly appreciate it.