It's extremely viable against certain enemies (and with one you can almost sleepwalk through a few dungeons) but it's almost useless against some trash mobs like the wolves in the Old Forest and, more importantly, Sigrune. So you'll want either a backup skillset or to play dedicated support to companions in those fights. Charmers are basically made for this kind of build and their natural focus on Presence meshes really well with both companions and summons.
The basic tricks are to wear light armor (to get the benefit of the Stylish perk) and to go with as much in the way of exposed bits as you can to maximize the effect of sexy underwear, whether that's using armor with the 'Exposed-X' tag or not wearing outer clothing to begin with. Personally I've found that dedicating a few points to Spellpower and learning Soul Arrow via training is a very handy way to contribute to the Sigrune battle and works really well against other foes as well. Beyond that it's kind of up to what sort of secondary build you want. You can add more tease attacks like Allure, you can add the various Song skills for support or (if you go with the Soul Arrow idea) even some offensive magic if you want to do some direct damage for a change. And like I said, Charmers work really well with summons whether it's your own or Ryn/Berry's.
