Pick up a "nylon" diver's sheath from the Randall shop. You can wash it and dry it in the clothes dryer before you put your #16 Special Fighter back in it and that problem is solved. I have 2 Navy divers who buy from me out of Pensacola. One has used his #16 "Diver's" for so long (over 20 years) that he has worn out 3 sheaths...but..."No Rust"!! It is, after all "stain"less" steel...not stain"proof" steel.
Best, Capt. Chris