I don't see anything about 420 cleaner at that link or anywhere on the Kannastor website like you quoted.
Edit: In fact, when I Google what you quoted, all I can find is you quoting the same on several other forum sites, but nothing from Kannastor referencing powdered 420 cleaner.
I only ask...
In that case, all the comments above yours in response to your question are irrelevant. They are all talking about domestic flights. As @invertedisdead suggested, you best research this topic and you'll soon learn it is a bad idea.
Sucks though. I haven't needed to cross that bridge yet, but...
Damn, just gave my Gr8r a PBW wash and I think I fucked up...
I tried washing it again with just water and vinegar but the PBW residue wouldn't budge. Would you guys worry about grinding with this?