Jamshyd,
Personally I've not gotten the chance to attempt this yet and I'm not sure I will in the near future. Not that I wouldn't like to, but I'm still having problems getting over my hump of having panic attacks when tripping. Today was a disaster on 50mg of 2cd and I had to abort the trip at 1.5 hours with a hefty dose of Klonopin and trichlorobutanol. I specifically took 2cd because it's always been friendly and gentle to me, and even it resulted in a full-blown panic attack.

8(
I was originally planning on using a 26.6mg cap of freebase rectally to assess bioavailability. While this certainly wouldn't be an ass-kicker of a trip even if 100% bioavailable, it would still be my first experience with DMT and should be enough to see if it's active via this route. Considering even 2cd threw me into a panic attack today, I'm not too comfortable with doing even a low dose of DMT right now. I'm sorry, but until I get a good comfort level back with the panic/anxiety thing, this experiment is on hold for me. If 2cd caused me a full-blown panic attack, DMT is the last compound I need to try to work with right now. Perhaps sometime later this summer I will give it a try when I've regained a bit of confidence. I will certianly bump this thread and post back my results here once I get a chance to try it. I'm just really frustrated right now with my inability to enjoy a psychedelic excursion as a result of panic attacks.
Based on the fact that DPT HCl is active when plugged (although it requires higher doses), I'm highly optimistic that DMT freebase will be active rectally as well. I know you've mentioned that 5-MeO-DMT isn't rectally active, but since DPT structurally resembles DMT more so than 5-MeO-DMT, I'm pretty confident it will work. Maybe the 5-MeO group causes some absorption issues?
I (REALLY) wish I could be the guinna pig for this right now, but I've got to work through my panic attack issues before attempting something like this. If someone here tries it in the meanwhile, please post your results. I'm very interested in this myself. I will avoid taking an MAOI at all costs, so I'm hoping I can enjoy plugged DMT freebase at some point without having to take an MAOI. I have no desire to smoke DMT either. Although short-acting, the rapid comeup/ego-loss when smoking spells certain disaster to me if I'm currently having issues with panic attacks.
As far as this 200mg report goes, then if someone plugged 200mg of DMT, then they should expect to trip pretty damn hard.

The rectal route may end up being pretty efficient, but even if it is like DPT and takes a bit more, 200mg is still a pretty hefty dose.
Take care and be safe.
-gp