trying to capture the tone one hears from another player, especially like Hendrix and Clapton, can be difficult. these two use some effects, but they are both killer players with incredible technique...tone for sure is in their fingers.
I am not sure what slide techniques you are pointing out. they both use double stops (two fingers on two strings) when they slide up or down the neck. sometimes they bend both or just one string. that is a good technique that can be had with practice.