This one I have personal experience with. I was in a local health food store to buy some culinary herbs, and noticed funny cones at the checkout. When I asked about them, I was told they sucked wax out of the ear.
On a later visit, when I began asking more questions, including how a suction could pull something when there was no connection allowing air to enter the ear canal for a flow to be established, I wasn't getting any clear answer other than people were buying them and offering treatments. Eventually, I told the store owner that she really shouldn't be selling things that were obviously scams. One thing led to another and I was thrown out of the store. Last I checked, they were still for sale.
This woman got taken for a $105.00 lesson, but then applied some critical thought and experimentation.