When owning a home, there is obviously up keep and repairs to do as over time, things get old. Recently my brother and his wife's key kept sticking in their front door, and it happened to deteriorate pretty quickly so that when I came to kitten sit for them; I couldn't get the key in the door and had to phone my brother. Finally with some pointers on the phone from him and some wiggling and pushing on my side, I got the key in the door and got the door open.
But when I came back again after the weekend the key went in easily. And what they had done is put olive oil in the key hole and what a difference! It is like a brand new lock and I was amazed, because I thought they would have to go buy a completely new door handle and lock system.
Anyway so I when I finally go around to my mums and stepfathers place I suggested they do the same thing as their lock was getting stiffer and harder to get the key in and it worked! It's like a brand new lock! Good on the purse. better for the environment and will save you a lot of time if you are a home owner.
So, if you have been having problems with your key, whether you own a house or are fed-up waiting for your landlord/lady to fix it, try some olive oil, or vegetable oil. The one good thing about using these kinds of oils is that they are cheap and don't smell.