I'm so sorry to hear of your family member battling cancer. It's not easy on the mind or body.
Food grade Diatomaceous Earth, silica, has many health benefits, but should not be used in excess. And try hard not to breathe it in. It's fine dust and when you deal with it much can get into the air. I took it for a while. A small amount. It made me more constipated than at any other time in my life. Seriously. But just look it up. You'll be impressed.
One bad thing about the claims is that alkaline/acid manipulation is pseudoscience, IMO. The body has over 200 mechanisms to regulate Ph. Even breathing is used for this. You cannot defeat it for very long unless you are very very ill. The body even makes its own sodium bicarbonate (baking soda) to regulate acid.
Here's an interesting site about fake science
https://www.chem1.com/CQ/ionbunk.html Though this page is speaking of ionized water it is a similar thing.
I'm recently taking DMG on a daily basis, but not for cancer prevention. For oxygenation of cells. This is one supplement that I do not want to do without since it is highly beneficial to health. As a result, when you take DMG supplement, it goes a long way to improve oxygenation.
https://www.klusster.com/portfolios/whole-family-products/contents/9103 Search other references of DMG.
Now, don't get me wrong about the use of natural medicine. I totally believe in the use of natural substances for the prevention of diseases including cancer. The problem is that there are no one-size-fits-all cancers. Once I get cancer, I find the best appropriate science. I have experience with this as a cancer survivor.