Is that really necessary? Rue is not toxic. I really am not sure where some people keep getting this idea from, the only thing i've ever heard about Rue being "toxic" is that it contains Vasicine and Vasicinone which simply shouldn't be consumed by pregnant women because of their potential to induce abortion, though i'd argue that, even if safe, pregnant women likely probably shouldn't be consuming Harmalas in any form, whether Rue, Caapi, or extracts, even though some reportedly have with Caapi.
But no, Rue is not toxic, i would know, i've been dosing it on the daily/near daily for 12 straight years now, usually taking 3 to 4 grams of Rue nightly and let the Harmala reverse tolerance build up and get stronger and stronger and then all the side-effects go away and it cleans up and feels pretty much as clean as any pharmaceutical anti-depressant. You can also counteract it's GABA-A inverse agonism by mixing in a GABAergic like Lemon Balm tea for example to clean up the bodyload until the side-effects go away. Aside from that, it is a more forceful purgative than Caapi due to the higher Harmaline content in Rue, however, the purgative effect too goes away with regular consumption.
Also, you can adjust the Harmine to Harmaline ratio in Rue, either by adding pure Harmine (or alternatively Caapi) to the Rue, or by doing a light roast Rue (not a medium or dark roast) which will break down the Harmaline content while maintaining the Harmine content and use that instead of the raw Rue, so that you can build up Harmine's reverse tolerance some, you can even take just pure Harmine itself for awhile, same thing, and then after Harmine's reverse tolerance is built up a good bit you can switch to using raw Rue and from then on Harmine is the dominant Harmala in the Rue while Harmaline is either secondary or off in the background, depending on Rue dosage. So like for example, what i did was take light roast Rue at 2.5 grams for a good while, and then switched over to using raw Rue, and ever since Harmine has been far ahead in the lead with Harmaline behind it, it feels a lot better that way, and also cleans it up nicely. I recommend it.
Also i personally have never found THH to be necessary. Can it contribute? most certainly. Is it a requirement/necessity for Ayahuasca? no, as Harmine and Harmaline work just fine.
Also you don't lose the magick with this stuff, at least orally, i took it daily/near daily for 4 years straight. And as far as smoked Changa/DMT goes, ime so long as Harmalas are involved, i've never developed any tolerance to DMT, smoked or orally, sure you get used to it to some degree, but the magick never goes away, not by a long shot lol.
Edit - Also, Rue definitely isn't garbage, it's just as capable of what Caapi is capable of, to me Caapi and Rue are both the same medicine, just different flavors. I've mainly used Rue for most of my experimentation, and it's been the best ally and teacher and guide and medicine that i could've ever asked for, and it's potent, and cheap, which certainly doesn't reflect in it's quality because it's of very fine quality, you just have to know how best to work with it. And just like with Caapi, you can also add an extremely wide variety of different admixture plants to the Rue, in order to alter it to various degrees, or to clean up how it feels, or to add other benefits, etc. I see absolutely no reason to use Caapi when i have Rue, and honestly people who act like Caapi is "all that" and that Rue is in any way inferior, they clearly don't understand this medicine at all and should go back to school, imo.