I agree with what zampilot and Youngblood have said, but will add that I don't think you have to worry about it as much as on other rifles. The SVT40 gas system design seems to be less sensitive to the presence of oil than the M1's or M14's. The system is shorter, a little "looser" and more forgiving.
Very true ... and, quite frankly, I have forgotten the "quick-clean of the fwd gas parts" on a few occasions and noticed no issues ... well, perhaps, those pieces were a bit dirtier than they normally get, but ... <shrug> 
I have had good luck with cleaning the gas parts first and oiling them with G96 and letting them sit for awhile while I clean the rest of the rifle. When I get back to putting the gas system back together I wipe the parts down to get any excess oil off of them. I haven't had a problem with leaveing a slight film of oil on them with the next range session or next cleaning.