Chaos Magick is particularly suited to defensive magick, as it is so easy to adopt even the most potent spells into you average routine. If you want a purification spell, simply attach the means to your hand washing routine, so that every time you wash with soap you're washing away all of the negative intentions attached to you (for best results, use nonantibacterial). Use this same form to attach meaning to all of your daily activities, so that simply by existing you weave a form of protection around yourself. Super easy.
0MAGICK is, in my opinion, offers a more potent form of protection, in that it believes all of the spells have already been cast, what we're living is only their outworkings, the spells we invoe are mere reflections, sparks, reverberations of the original. From that perspective, there is nothing you can, and nothing you should want, to do. Do nothing and you'll be fine