lubricating before picking

[cryptocat]

Sorry, but I NEVER expected a degreaser spray to be oily

Why not? Greases are lubricants (often a paraffin) that have a high viscosity to keep them where the lubrication is needed. That implies they're pretty long molecules. You can dissolve a long hydrocarbon in a short one - so a heavy grease can be dissolved in a lighter oil to flush it away.

[Engineer]

You are right, I just didn't expect something that was a degreaser to leave an oily film behind it. I suppose I was expecting somthing more like a detergent or "swarfega" that would leave a faily clean surface behind.

This is very good at breaking up thick grease alright, but you need something else afterwards if you want a clean surface as it seems to be a light, penetrating oil.

[mongo]

Using 'Brake Cleaner' is a fantastic product, Kleen Flo for example. It breaks down the carbon and other particles, then they wash out. Let all of the solution out of the guts and then use a couple shots of WD40, this will displace any other crap in the lock.
Finaly, use a teflon or silcone spray to lube it. Use only enough to get the lock working. Wipe up any excess product. Remembering that any wet surface will attract dust, dirt and water.
When I am in the dessert like conditions, I blow dry the lock with compressed dry air and then place a small baggy with and elastic band around it.
Locks are fairly in-expensive, but the stuff I keep behind the lock is even more expensive.
Preventive maintenance...get some