No fire-arm lubrication should ever
come near an airsoft gun.
Just because these are more realistic doesn't mean petroleum based lubricants wont destroy them. I would suggest a high quality Molybdenum grease (such as Airsoft Research Syndicate's Sticky-G Moly) for anywhere where there is metal on metal or hard plastic on metal contact, and I'd suggest a Silicon Grease for anywhere that has "sealing" properties.
I personally use, carry and have had FANTASTIC
results with the ARS line of greases