I received my switch about two hours ago, wiped it down, swapped the fans (there were fans installed), and plugged it in. As others have said, the oil isn't heavy, I used a washcloth and an orange-based cleaner for a quick wipedown. I wish I'd thought to use alcohol. If I find that the switch is fully functional, I'll go through a thorough cleaning.
My switch had a fairly old firmware version on it, so I downloaded the latest and attempted to upgrade it. I'll save you each the long story and some googling, when you go download the firmware, you'll also want to download version 1.3.7.18. The installed version was old enough that you can't update directly to 1.4.1.03. I found a post somewhere that said you have to go to 1.3.7.18 first, so I did that. In my case, I was able to update the bootloader (with the file from 1.4.1.0.3), but the firmware upload would fail with "illegal software format" until I uploaded 1.3.7.18, rebooted, then uploaded 1.4.1.03.
I am a bit confused, though, and I would appreciate some wisdom. I've replaced the fans, but they're not running. I used 2 Noctua NF-A4x10, which should work (12v, 3-pin). However, in the health section of the web interface, I see "Fan Status: Fail". Any ideas on how would one reset that or correct it?