It seems many users of the nexus are interested in tobacco due to it's use in shamanism in South America. Although traditional Mapacho Tobacco is probably the tobacco of choice because of its maoi qualities, it is hard the find unless you look online were it's usually only sold in huge qualities. That's why I thought I should mention dokha.
Dokha tabacco is a pipe tobacco from the middle east and is traditionally (some brands add flavors nowadays) chemical/additive/preservative free since it is simply dried in the desert sun. It is also very potent, a small hit will get you very buzzed/light headed especially if you don't smoke tobacco regularly, and too large a hit will have you knocked out drooling (unfortunately speaking from experience here!). It is traditionally smoked through a medwakh which is basically a pipe with a tiny bowl but you can put a small pinch on a bowl of weed as well. In North America it can be found in most smokeshops that also sell hookah.
It also has great purging potential as I have seen people highly intoxicated on alcohol projectile vomit from this stuff. So check it out if inducing purging is of interst to you while on ayahuasca. I am not familiar with tobacco shamanism but I imagine it could fulfil many of the same functions since it is also very potent and natural.
If you decide to smoke dokha try it out before you are on psychedelics, and make sure you are sitting down and have something to rest against. Also tobacco is tobacco so still carginogenic etc.
I'd link to some articles but they all appear linked to stores, so Google (or duckduckgo!) Is your friend.
He who sees the infinite in all things sees God. He who sees the ratio only sees himself only. -William Blake There is no natural religion.
People in the past never lived in ecological balance with nature, they died in ecological balance with nature -Hans Rosling
Nothing is something worth doing -Sphongle