Like Alka-Seltzer for your bathwater, these items bubble when submerged, and most release a fragrance. More fun than effective, the scent released by the fizz bomb won't last long.
Try pouring-some cologne or body splash into hot bathwater. The heat releases the fragrance, filling the bathroom and the water, surrounding you with the scent. The scent from this bath won't adhere to your skin, however, so it is not effective for layering.
Bath oil comes in many forms: foams, beads that dissolve when placed in hot water, and even bubbling bath oil. The resulting film that forms atop the bathwater adheres to the skin, softly coating the body in a mantilla of fragrance. Fragrance is more concentrated in bath oil, which means it will last longer on the skin. The oil also moisturizes the skin, heightening the pleasure factor.
The most familiar way to add fragrance to your bath, bubble baths are made with a lot of detergents, which can be slightly drying to the skin, although many formulas are now made with conditioners. A bubble bath is more about relaxation and indulgence than anything else, since the fragrance does not last long on the skin once you leave the bath. One way to prolong the fun: Be sure not to add soap to the bathwater, even just by letting the bar fall into the water, as this causes the bubbles to evaporate.