I've always just hung them to dry upside down in a bunch. But, you can use the silica gel.

Hanging upside down is easiest, in a bunch of no more than three stems. It's the stems that really need drying -- the flower is practically all dried when you pick it. The stems can take two weeks to dry, even in the hot loft of a barn. You'll know they're done when you can put your finger under the flower head, push it up, and the stem doesn't bend. Some people have trouble getting the stems to dry and end up removing the stems and substituting floral wire.