Need information I can trust- wife is on 3rd round of chemo wants to try invermectin [View all]

I'll try to keep this post short.
My wife:
Diagnosed with 2 types of breast cancer and CLL in 2019 when she was 53.
Double mastectomy and chemo.
Something wrong with chemo port causing 5 infections resulting in sepsis and endocarditis that destroyed aortic valve, requiring valve replacement and then pacemaker defibrillator.
First recurrence of cancer, requiring radiation and chemo.
Replacement of first heart valve due to stenosis from radiation.
We are now in second recurrence of cancer and third round of chemo. This is supposed to be more targeted, but has caused her severe diarhhea, leading to multiple UTIs, and then pleural effusion requiring more hospitalizations.
At this point the blunt way of putting things is the oncologist is saying it is either chemo or cancer.
My wife is being steered to invermectin by her sweet but wing-nut aunt because she is being destroyed by the chemo and feels she has no life as leaving the house is difficult.
I don't know what to say to her. Is there any harm to trying it?