They didn't have graphite so I picked up WD-40 dry lube and now it takes the key just fine.

Agreed on using graphite, which is a dry powder.
WD40 is an oil/waxy compound which uses thin oil to penetrate and the waxy component remains as a coating. Silicone also leave a coating. Any regular oil also leaves a coating. Anything that leaves an oily or waxy coating collects dirt and just gets gummier. Graphite, being a dry, extremely fine powder that is very slippery, provides lubrication to lock components without collecting dirt. Squirt a little bit in and work the key to get the graphite worked into not just the keyway but all the pins.  A little goes a long way. I have a 1/2oz. squeeze tube similar to this (photo ) that I've had for probably 20 years. An aerosol can would be overkill for home use, but maybe useful in a commercial shop.
Edit: I looked at Mike's link - that aerolsol product says it "dries quickly" and "leaves a protective coating". The pins in a lock are very small and close tolerance - I wouldn't want any coating on them at all, IMHO.

Kolsen, what did you spray in the lock?  A lot of times people think WD-40 is a silicone spray.  It is not.  The regular blue/yellow label WD-40 is a thin oil.  The black label WD-40 IS silicone.

Assuming you used regular WD-40 to lube the lock, just liberally apply the 3-in-1 lock spray.  Its solvent/carrier will flush the WD-40 out of the lock.  

dr mini.  you are quite right..  it will turn to JELLO..  me thinks  you will need to buy a USED switch.. ( I looked I did NOT have good used one..  laterbc

Now, how's the best way for him to get the silicon out? I would think that spraying graphite on top of the silicon would be a problem. Thoughts?

Graphite, sure thanks will run down to Auto Zone right now. 

As above.  Graphite.  3-in-1 makes a graphite spray with wand so you can reach into the keyslot.

It should be available at the DIY stores and parts stores.  It is definitely available from Amazon.  See link below.

https://www.amazon.com/3-ONE-120070-Lock-Lube/dp/B00URCHHBQ/ref=sr_1_1?ie=UTF8&qid=1544294639&sr=8-1&keywords=3+in+1+dry+lock+lube
.

put graphite in there not silicon.   

Having trouble pulling the key out of my ignition.  A squirt of silicon helps but only temporarily.  Is there something that needs to be tightened up or just replaced.  I haven't opened it up yet.  It's on a 1993 mini.