I don't have any personal experience with 2ct7, but I have plugged a few phens including 2cd, 2ce, 2ct21 and 2ct2. I've never had nausea plugging any of them, but then again, I have never had nausea from any RC orally either. I guess I'm just lucky that way.
While it may help with the nausea, my experience is has been that the absorption and comeup using this route is much quicker than oral ingestion. But each of them is a little different. So just be aware you may come on really fast. Orally 2ct2 takes a good 2-2.5 hours for me to get going really well, but rectally, it's like being strapped to a rocket once it starts to climb. :D
The first time I did 2cd plugged, I got kind of scared how quickly it started to climb and was actually glad when it stopped and I knew it had peaked. Since then I've almost doubled my plugged dose and it's been great, but that first time scared the shit out of me since I wasn't expecting it to climb like that. I was worried I had taken way too much for that route.
Also, be VERY CAREFUL with your dose the first time or so you plug it and increase your doses graudually. My experience with the phens above would make me guess that most of them are around 2-3x as potent when plugged. So if you want to play it safe, I would recommend only starting at 1/3 of your oral dose when you plug it the first time and see how it goes. Also, the dose response curve seems to climb a bit more quickly than by the oral route. Even dosing at 1/3-1/2 of an oral dose, the effects seems to intensify with much smaller dose increases for me when plugged.
Good luck and be safe.
-gp