They can be made to serve the same purpose with wonderful results... this encompasses not just the phsyical disciplines of breath, asana , etc. but the mindful tabboo breaking that is used so effectively by some tantric sects . They work well as puja which I've found most effective to incorp. into everything from bhakti to Astarte rites.
I have an ancient essay on bdsm as Thelemic practice that can be found at http://www.caoto.org