I recently acquired a lot (5) of Gillette razors which included a superspeed. the silo or barn doors look to be in good shape but don't open. I think the problem is in the twist to open mechanism.
Around the twisting part at the bottom of the handle there is a black. green buildup that smacks of hard water and shaving byproducts. My initial though was to use CLR (calcium, lime, rust) cleaner... but I didn't see that recommended in the forums. Is that not a viable option?? I was wonder what your thoughts on the topic were.