I think that "rectal administration" of any psychedelic would most likely serve to put one in a very "awkward head space" to put it lightly...probably not the best way to start a trip....
I believe there is a You tube video where someone talks about taking 500mg's of DMT rectally --obviously that was way too much for the person but either way it did NOT sound at all enjoyable.
I have worked with morning glories for many years and while I have never tried any fancy type of LSA or LSH extractions I have had some serious success....
There is a couple weird things about Morning glories one thing I have noticed is that there is pretty much no way around having a pretty large body load before your trip begins....
but I do believe this nausea can be minimalized.
The main thing I have noticed about morning glories is that for best results they have to be worked with while FRESH.
I believe that there the alkaloid make up of morning glories includes something called the ergine ring which is made up of the lysergic amides. this ring is extremely delicate to degradation. When the ergine ring decays what you essentially have is alkaloids that will make most people super, super nauseated and also sleepy to boot. Anyone who has tried to eat straight up dried morning glory powder can attest to the horrors involved.
My best least sickening MG experiences were with seeds I picked right off the vine and ate immediately...One method I used is to just chew up huge amount of the white inner seeds and just swallow the juice...spitting out all of the plant matter. A cold water extraction also works but I noticed it only has a shelf life of about 24 hours before the LSA starts to decay into something bad.
If I can't get fresh ones I germinate the seeds in acidified water and then eat the fresh two day old seedlings...works good but slightly more nauseating than fresh off the vine seeds.
There is a tek I also used that involved washing the ground fresh seeds in everclear, letting them soak good for about 10-20 minutes depending on how much plant matter then I throw away the first pull.
(my first time I did this I thought the goods would be in the first pull so I ate the result of that...so it made me throw up for 3 hours,,,,no trip. this is how I realized the first alcohol pull gets the "nasty bits" out.
Then I let the leftover morning glory mush dry out slowly in a dark place that is not too hot.
Once the mush is dry I soaked it in everclear once more this time keeping the resulting pull. then evaporate the everclear slowly on a glass dish and presto....crude morning glory extraction that does not make one so freaking ill.
And why do you look at the speck in your brother's eye, but do not percieve the plank in your own eye? Or how can you say to your brother, "brother let me remove the speck from your eye", when you yourself do not see the plank that is in your own eye?-Yeshua ben Yoseph