Stainless steel water bottle has salt stuck in it.?

so a while back i got bronchitis. My buddy told me that i should either throw away or figure out how to clean my stainless steel water bottle. Then I decided that if i filled it with extremely salty water, and left it there for a month or two it would die. Well that worked, Or i hope it did, but now theirs salt crystalized onto the inside of the waterbottle. I don't want to have to buy another one, because i have lots of memories with this one. And i decorated it really nicely. Any idea how to get the salt thats now stuck in the inside. And lets not be the old lady who swallowed a fly here. I want something that will work, but not cause another problem. Thanks yall. Much love.