I’m sure you know this, and you’re just being facetious with the resident drunken anarchist. But for the benefit of those more easily led astray…
These don’t have a proper seal, just a loose bit of plastic against the end where the blades protrude from. It’s not like a round shaft where a rotary lipped seal can easily form a total seal against the oil.
I laughed at his post because although he have have filled it with chain oil, he hasn’t yet realised that there’s none left inside it unless he’s stored it standing up for the last 15 years and not used it.
Your workshop is full of trimmers for the reason that people assume once it’s ’filled with grease’ then it’s good. What actually happens is that they get hot with use, the grease gets liquid, and escapes from the blade end. And then it’s not replaced. What’s left inside emulsifies with the loss of the oil component of the grease through heat and ends up in the familiar waxy looking crap everywhere in the head except where it’s needed- on the gears and in particular the con rod bearings.
stick a grease nipple into the fitting and grease it every other time it’s used and they will not fail.