That is the question. One of my teammates was told to put a few drops of oil in his SLG's ASA so the regulator stays lubricated. What is that going to hurt??

I know the reg and bolt should be lubed with grease.

it shouldnt hurt it as long as its just on the threads not up in the pin

Dow 33 grease is all he needs.

Will oiling cause harm to the internals?

with the slg it shouldnt since the its a pancake sileniod(same as a spyder as it just trippes the sear) and not a regular one like on the dm/pm that control air flow

it might cause erractic operation or inconsistency and if that happens just pull the internals and clean and relube them and clean your barrel to i found that out with my old cocker