Using a Desiccant to Control Rh?

I'm in mid-flowering now (week 6) and getting RH of 60-70%, I'm concerned about bud rot, and also about media not getting dry (I water once a week and even then it's still moist). Will a desiccant like the one you put in closets help me with this? Has anyone tried it?

I tried one and it definitely removed water coz I could see it in the deposit but it wasn't enough. After looking for days I think the only thing that really works is a dehumidifier.

The one I used:

http://src.discounto.de/pics/Angebot/36467/55420_Humydry-Compact-Raumentfeuchter-36467_xxl.jpg

just a drop in a bucket, u say?

yes, exactly