It's not a good idea to use oil of any kind on the bolt or pellet probe as any excess will inevitably creep down into the hammer tube causing inconsistent shots as it slows the hammer travel down a bit then gets thrown clear, then accumulates and clears in a random-ish cycle until it's all stripped down and cleaned out. A smear of grease occasionally on the larger diameter of the bolt or probe should not migrate into the hammer mechanism and cause such problems. Just a smear and only occasionally is all that's needed.
Silicone "oil" is a good rubber and plastics lubricant but useless for metal to metal wearing surfaces, it actually causes more wear rather than reducing it. For metal to metal use molybdenum disulphide based grease, for the probe (metal) to the probe bearing (Delrin, an engineering bearing grade of plastic) moly grease is fine.
The O ring seal would be fine with silicone "oil" but using Abbey SM50 is better as it is a mix of silicone and molybdenum disulphide which is capable of metal to metal lubrication as well as keeping the O ring in good condition. Although there is no actual metal to metal contact on the front half of the probe SM50 will not cause galling if it does come into any metal/metal load bearing areas however it should not be used in excess as it can migrate into the hammer tube causing inconsistent hammer strike and hence inconsistent muzzle velocity.
That is why less is best in this particular case.