I posted about a month ago about the lock-down knob on my Slim being darn near impossible to twist. It was suggested that I soak it in hot water and soap, and that did free it up for a time. Now, its back to being difficult to twist. Is another soak in order? Is that something that has to be done on a regular basis? I clean the razor with a toothbrush after every shave, so that should help. Of course, that doesn't get the internals of the mechanism.