Potassium bad for glioblastoma

Hi all
I was on the web searching and researching as always the other night and I came across something that was new to me anyway. There was a blog inspire.com I think it was on and there was a Gbm patient there her and her husband where both scenitescs, and they came to the conclusion that they was going to cut out all potassium in order to inhibit prolife and migration.
I think that was in 2011 and she is now cancer free.
Since reading this I have reasearched it some more and apparently it's correct that potassium channels do indeed play a role in prolife and migration of Gbm
So I question is
She did it by completely not eating anything that contained potassium.
I no there are drugs for potassium channel blockers would these be as effective.
And Stephen I would love to hear your views on the matter
Hope all u guys are well

Magnesium and Potassium supplements

I have read that our cocktails can deplete magnesium and Potassium among other things.  Does anyone specifically supplement with these?  What kind?  Source?  Thanks.
Aunt Jo