Wave attacks are a great tactic to use to get Great Dragon armor and Elemental Dragon eggs and armor. This has been used for many years and has proven to be effective.
The troops used for this are generally easy to replace troops such as LBMs, Spies, and SSDs. If you are worried about losing a small amount of easily replaced troops to get your Outposts, your priorities are not correct for this game.
This technique does not work for Anthropus Talismans. The basic premise of "waving" is to clear the location of all troops; therefore, decreasing the damage your Guardian Dragons incur and increasing the maximum number of attacks. More attacks = more chances to obtain your egg or armor.