Not so unfounded to the many people whose lives have been saved. Silver is a trace mineral found in nature (so is iodine for that matter) and oleander is a plant. Antibiotics are largely concocted in the labs of Big Pharma and come laden with side effects.
No doubt a healthy lifestyle plays a big part in the success of many natural protocols and supplements and I too would recommend a healthy lifestyle over the longterm use of ANY supplement, although some conditions (such as having had cancer or having HIV) might make it wise to continue supplementation at a lesser preventive rate.
A healthy lifestyle alone has not proven successful in beating or managing HIV and in today's world of increased toxins and depleted soils is proving less and less effective by itself in overcoming cancer and preventing its return.