I tried that approach and my experience was not positive. Over time, the oil embrittled the plastic parts on the motherboard so that the PCI slots just crumbled

I tried that approach and my experience was not positive. Over time, the oil embrittled the plastic parts on the motherboard so that the PCI slots just crumbled. The smell was not an issue for me, I put the entire contraption onto a balcony and used a long VGA cable.