Black seed oil has several applications and benefits for problematic skin conditions. The oil is found in many health foods stores and pharmacies. Examples of applications for beauty and skin include:
It's important to read labels on any product before you use it, whether it's a gel, conditioner, shampoo, serum, or what have you. But no, all gels are not bad for your hair. 3a and strictly CG since August 2007.
For well-defined curls, products that are not oil-based will give you better results. When you don't want to wear your hair in ringlet form, using oil is fine and won't disrupt your style, but water-based gel-like products give good hold while keeping frizz at bay.