Someone told me to spray my tent with something called "Campdry". Said it would cut down on condensation and waterproof the tent.

 

Has anyone used Campdry before? Any warnings?

Nope, at least not that particular brand. I've used other brands and they will help water repellancy but most won't help with condensation no matter what the label says. The only condensation cure I've seen is ventalation.

 

I'd be more concerned with seam sealing your tent. I use any old brand of seam sealer and apply it with an oral syringe. It's much cleaner than a brush although you will need to keep one handy when seam sealing to level out heavy deposits of sealer.