Hello and welcome!
I have never been to a retreat personally so I can't really comment on that. There are a lot of scams out there so do be careful! I don't believe it is necessary to travel across the world to find and begin healing within yourself. However, there is immense potential for healing in a place like that, assuming it is legitimate, so I cannot discount the possible benefits.
Here is some more information on the subject from others on the Nexus, if interested.
I do have a lot of experience with using psychedelics at home though. Mushrooms and cactus are some good alternatives to DMT, mushrooms being particularly close, even on a molecular level. Both are incredibly easy to grow and well worth the time and effort put into it. Mushrooms only take about 6-7 weeks to go from inoculating substrate to the first flush using a multi spore syringe. Cactus are a quite a bit slower growing, of course. Growing your own entheogens helps you build a solid relationship with the plant(s) from birth to ingestion and beyond. This isn't always an option for everyone but it is definitely something to consider.
Some organizations have been doing studies that suggest mushrooms can be used successfully as a treatment for depression. This is not some sort of cure-all of course, but it is another thing to think about. You can read more about it
here.
For your first experience (with any psychedelic), if you were to do it at home, it may be wise to have a trusted friend or spouse with you or nearby to act as a sitter. Take special care when it comes to set and setting and plan ahead. Don't have any pressing matters to attend to for at least 24 hours, turn off the cell phone, lock the door, make sure no one will show up unannounced and startle you, have some music that you enjoy playing in the background. Be creative and enjoy yourself!
Anyway, I'm sure others with more experience dealing with Aya retreats will chime in with more details. Hopefully you find some of this information useful! Have a good day!
Peace
Edit: I forgot to mention that brewing your own Ayahuasca at home isn't a difficult process at all either. Start low and build your way up with dosages and be sure not to mix harmalas with any MAIOs or other substances unless they are known to be safe.
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