You are correct, it is a crock. The last time the entire earth was under ice was 3 or 4 billion years ago, snowball earth, doesn't happen every 100,000 years.
""""The last time the entire earth was under ice was 3 or 4 billion years ago""""
PSST!
You mean 3 or 4 MILLION?
The Earth is only a little over 4 billion years old.
I know where your coming from, though.