I used spray silicone lubricant on a door lock that was hard to get a key in and out of and it was a massive improvement - highly recommended. I didn't time the

I used spray silicone lubricant on a door lock that was hard to get a key in and out of and it was a massive improvement - highly recommended. I didn't time the improvement but it was night and day. There's been no problem with the lock "gathering dust", so no need to get graphite powder for this job.