As one of its daily deals, 13 Deals offers this 0.5-oz. "Poo" Toilet Spray in five scents for $3.99 with free shipping. (The scent is chosen at random.) That's $5 off list and the lowest total price we could find. This spray purportedly stops bathroom odors before they begin by creating a film over toilet water that will trap odors.

Note that if you buy two or more, the price will drop to $2.99 per spay.