I've done 5-meo many times. Yes, it works in the GVG, both the salt and the freebase. The freebase is noticeably moar potent than the salt. If you have the freebase, start at 2 mgs, if the salt I recommend 2-5 mgs to start. I had a hardcore OD on 22 mgs of the freebase and haven't been able to do it since.
I suggest a sitter who is experienced with psychedelics, 5-meo if possible. I also suggest a purge bucket. Schedule a LOT moar time than you would for N,N. On my BIG trip I was under for close to an hour and unable to speak for well over an hour after I "woke up." I said weird things under the influence that I did not recall. My sitter/husband was so freaked out he wouldn't repeat them to me.
You get one hit, maaayyybee two. Plan on one. It hits A LOT faster than N,N, A LOT. I take the hit, and before I even set down the pipe, it's hitting me like a physical wall.
I found it difficult to resist - the body load is huge and again the timing. My resistance instantly yielded a rearing up reaction including extreme drooling and nausea. I never actually purged, but the bucket was useful nonetheless. The moment I was able to surrender and lay back, these physical symptoms faded and everything got pleasant, though incredibly intense.
Lower doses lead to a feeling of euphoria, a bit of open eyed distortion, not much behind closed eyes, and a feeling of arousal. Higher doses yielded a yellowish light behind eyes and a full on body/soul orgasm that caused me to gasp and moan according to my sitter.
Higher doses slammed me right into the Yellow-White light and memory wipe and lasted a long time. Sometimes they felt confusing/difficult, othertimes deeply pleasant/spiritual. Every single time there was a lack of visuals especially closed eye, other than the light. Higher open eye doses lead to a kind of distortion that is difficult to describe. I looked at my husband, at my cats, etc, and felt like I could see them in more than 4 dimensions. In fractal space and foward and backwards in time.
Also, with N,N, my eyes close, even if I try to keep them open on decent doses. But on all doses of 5-meo, my eyes would open and close throughout the experience.
I urge precise weighing, proceeding mg by mg and careful preparation. This material taxes my advanced tripping skills like few others.
Peace & Love