To gain the extra experience from the gloves while using another set of gloves for combat, wield the gloves used for combat while attacking the Dragon. Then, when the dragon is about to be killed, switching to the dragon slayer gloves will yield the appropriate experience bonus.
Many players prefer good combat gloves over the dragon slayer gloves against most dragons due to the higher hits. However, if fighting the King Black Dragon or Queen Black Dragon the attack bonus will noticeably increase your accuracy, making the dragon slayer gloves the better choice.
Keep in mind, these gloves WILL NOT appear under your gravestone, so if you die you will need to obtain a new pair.
The Gloves do not grant any bonus experience when used against Skeletal Wyverns.