That is a very good question! To tell you the truth - I don't know. It took me over 8 years to get the nasty chemical taste out of my herb. What helped me get it right was the following.
I always dry the same way so it wasn't my drying, same as curing...
My stuff got good when I backed off putting too many chemicals in it - I had the lame idea that more was better.
Another real help was I started using Final Phase to flush them. What it does is it strips the salt off the roots in soil. After the first use of it, the plants begin getting real thirsty which helps flush it out. Some people say they don't bother flushing... Anyway, the cool thing about Final Phase is it's fairly cheap - one teaspoon to a gal. and thats the ONLY thing you add to the water.
The best part is watching the freaking buds get about 1/5 bigger in size. They start growing little buds on top of the bud or colas! Very trippy to see a cola grow bigger when they are normally
done in size.
Good luck and HAVE FUN!