In general, be VERY skeptical of claims that herbal or alternative therapies can replace insulin treatment in cats or dogs. Please note that many of the charlatans and scammers discussed in this article had ads appearing on this wiki. See the phrases they use to try to hook you at Ad scams and Ad scams 2.
Some direct quotes from an abstract from Ohio State University about alternative treatments :
"Quackery is defined as "Promotion, for profit, of devices, services, plans or products that do not work, or which are untested.
"Quackery can delay a person from seeking care for their pet’s problem, be dangerous itself, and delay legitimate research to find an effective cure.
"Be wary of "experts" who say that:
They or their products can produce miracles.
Offer only testimonials to support their claims. (and only positive ones)
They have something to sell you. (usually at a handsome profit)