I wished I'd have read more caerfully Indian Joe, I read in one account of a manufacturer that they mixed with up to 7% moisture, not sure what the 7% was of though, 7% of ambient atmospheric moisture or 7% of mix volume or weight. The idea was that it could not detonate with a small amount of water in it while mixing.
Nothing lost though, if it's clumped I can dry it out and do it dryer. a tablespoon is very little water for the volume.
I've been reading so much the last few days that I can't say which article I was reading, but thinking it was of the rebel powder works, but even if that is the article I'm not sure which phase of tumbling it was, pre-tumbling the separate components or the whole mixture, and maybe they mixed damp and then dried before pressing.
BTW, I chickened out and shut her down for the night. OH YEAH! Someone somewhere was saying they checked tumbling occasionally to see that it wasn't too dry. Hmmm.