If you rub an onion on your foot with in 30 to 60 min, you will be able to feel the taste. This is because it travels through the blood stream.

This is a myth. While some strong-smelling compounds from onions can be absorbed through the skin and potentially reach your breath (which might give onion-like smell to your breath), you cannot actually 'taste' the onion through this method. Taste perception requires the substances to physically contact taste receptors in your mouth. The explanation about it traveling through the bloodstream to create taste is physiologically incorrect - taste is a localized sensory process, not a blood-borne one.