Hi Jill,
don't worry about the keto - in Dukan it' only slight and may not necessarily be detectable - I don't think I ever had a metallic taste or bad breath! Stick to the rules and see the weight come off. Watch your salt in take but no need to cut it all out. I'm sure sauerkraut etc would be fine, after all gherkins an capers are even allowed as a condiment on PP days and they *are* salty.
Just be a bit more careful than you used to be....
If you're worried about getting it right, if you don't already, post your menus (with vague quantities helps) into the menu thread and the others may be able to see if there is something in there that's tripping you up. Not eating ENOUGH protein can be one factor for example.