Substituting \ for \\ in column

I exported a column of thousands of salts from Mysql for hashcat. Every instance of the character \ was replaced with a double character \ in the exported column. (this won't even print a double \ so a am spelling out that they are double)

Is there a way to either sed or awk out the double \ and replace them with a single \ ?

Or is there a way to make mysql not export single \ as a double character?

I use the following mysql command: SELECT salt FROM user INTO OUTFILE 'salts' FIELDS TERMINATED BY ‘:' LINES TERMINATED BY '\n'

The salts are three characters long and appear to use every character on the keyboard.

I have tried the following sed command:

sed 's/\(.^C\1/\1/g' file.txt  

and it replaces double \ with single \ but it also gets rid of a few other instances of double characters that I don't want it to.