I have literally just done mine with brake cleaner and some cillit bang Then a bit of wd40 and it looked as good as new' took me ten minutes. Keep the key in so when it gets clean it doesn't fall apart.
The graphite stuff isn't sticky. Greases all tend to be sticky and get stickier with age and will collect crud so don't bother. Totally dry is almost better than old grease. White grease just starts white until it gets cruddy.
Kasp K30050 Graphite Powder https://www.amazon.co.uk/Kasp-K3005...coding=UTF8&psc=1&refRID=GVN7ZM4JC31AKD3X377N what would this be like WD-40 Specialist Dry Lubricant http://www.wd40.co.uk/wd-40-specialist/anti-friction-dry-ptfe-lubricant/
what a good old fasion pencil lead http://www.instructables.com/id/How-to-Lubricate-a-Lock-Using-Graphite-From-a-Penc/
I use a pencil sharpener and lead in me pencil. Don't need no inflatable, blow up things me. Oops wrong thread!