A yield of 2.6% from a fresh cactus seems highly unlikely. To assess the plausibility of this figure, take a look at the most excellent
cactus analysis thread, as well as
The Average Cactus Mescaline Content Mega-Thread and the
Post Your Mescaline Extraction Results thread. This will help put your figure into perspective.
It sounds as though that weight is including a certain amount of moisture and impurities (as in, non-mescaline substances). You'll want to be drying it out and doing an ice-cold acetone and MEK wash before
recrystallising, if it's purity you're looking for.
You could also consider sending a sample of it away to get analysed. Check the forum index, there are threads about this subject.
As far as ingestion goes, it's your call. By the sounds of it, you'd be happier to test it after a couple of further purification steps.
“There is a way of manipulating matter and energy so as to produce what modern scientists call 'a field of force'. The field acts on the observer and puts him in a privileged position vis-à-vis the universe. From this position he has access to the realities which are ordinarily hidden from us by time and space, matter and energy. This is what we call the Great Work."
― Jacques Bergier, quoting Fulcanelli