I don't use the flakes but i do use one ounce of MgCL2 liquid up to
my ankles in a basin for 1/2 hr. I am now tempted to use more
for an extreme condition I am battling and will probably do so
for a short period of time.
You can also get a bag of Nigari (MgCL2),
used to make tofu from "Ohsawa" for about $9.00.