RWS makes a lubricant specifically for your springer chamber (appropriately named chamber lube) that comes with a probe to apply directly down your transfer port hole.
I believe it's silicone based iirc.
As for applying moly lube to the spring without disassembly, I couldn't imagine it going well.Would just make a mess as the only way I could see it being romotely possible would be to try to probe some down the cocking slot, and even then you'd have no way to distribute the lube to the whole spring.