I have and continue to put three drops of oil in my ASA before and after every day of play. Immediately thereafter I fire my marker about 15-20 times to distribute the oil throughout my marker. I have been doing this since 1996 or so and have yet to have anything blow up. I can think of a single way that putting oil in your ASA that would allow - make that FORCE 'cause that's what'd take - the oil into your HPA tank/reg. According to all the physics I know, any gas under pressure will expand in the direction of lesser pressure (through your marker). It would be impossible for a 200 psi operating system to blow gas into a 3000 psi HPA tank.
Black PIMP milled by DAVE as soon as my $350/mo. heating bills quit coming in
ER clamping feed
New frame w/Blue single blade & Dye Checker panels
Full pipe with blue 14" Stiffi
Z code Halo B w/rip
Centerflag Hyperflow 68/4500