Best way to clean a RAM slot?

i recently bought new RAM, but the slots in which I want to put them are very old and have never been used. I would like to clean them in case there is some kind of corrosion.

i’ve read that cleaning them with a moistened RAM with contact cleaner and taking it in/out the slot a few times would do the job, but I’m afraid that with the friction i could set it on fire, or is it very unlikely?

This is the contact cleaner that I’m going to use. (i’ve no other choice)