Can I rehydrate?

I had my cut buds hanging and drying in a tent and the humidity was at 70 and above. So I put a small heater in the tent. When ever the heater was off the humidity went up. One night after noticing the humidity at 71 I turned the heater on overnight and most of the next day. The morning after I decided to jar the buds I found the buds as dry as my throat after smoking a good joint. I put the buds in jars anyway and packed it with humi-paks. Before I put the packets in the humidity was at about 30. Will the humi-paks rehydrated the buds so that they can cure or am I just pissing in the wind with hope. Please don’t tell me that 6 months of grow is down the drain.

I'm sorry to say, but at this point not a lot can be done. You can try to bring moisture back but that won't do much for smell and taste. You can use an orange peel fresh lettuce leaf but, that only helps with moisture not taste smell or flavor

It's not down the drain exactly but it sounds like you stopped the curing process with very low humidity and probably too much heat. I've heard of people trying all manner of fixes for weed that's too dry but the results are very rarely good. The drying and curing process is where you really make it or break it so setting up a drying environment that's both cool and the right humidity range can be difficult but it's worth spending time and some money on if you plan on continuing to grow. 60 degrees and 60 percent humidity is ideal but it can be a little warmer as long as they stay close to 60% humidity in my experience.
You can always use the dried bud for Green Dragon tincture or edibles where the dry harshness is not an issue.

Drying/curing is the slow process of off-gassing from your plant material. There's no such thing as "re-hydrating" your buds. Exposing dried plant material to moisture isn't the opposite of drying/curing, it just makes your buds wet and exposes them to spores/molds/fungus that thrive in damp conditions.

If they were only "crispy" for one day, I'm betting you're fine. Don't open the jars for about 2 weeks, and you'll be amazed at how much the material seems to "re-hydrate" during the curing process.

It really depends on whether they were crispy all the way to the center of the buds. If the centers of the buds were still moist then jarring them should draw some of that moisture to the surface of the buds and they may even out over time. If they were crispy to the center then what you have is what you have. The lesson for next time is don't use a heater to bring your humidity down unless your Temps are way too low. A dehumidifier with the ability to turn on and off based on rH is crucial to the drying process.

Just smoke it, sheesh. You will still get high, promise.