Thyme oil is incredibly anti-microbial. Visit this site for more information as well as a link to the EPA fact sheet on thymol - the active ingredient in thyme oil. The essential oil is so strong that it can't be used on your skin undiluted. I know because I've tried and, oh, the burn.
To make a sanitizing spray, use fresh thyme to make an infused vinegar. For this I would use extra thyme and distilled white vinegar. Once the sanitizer has sat for a couple weeks and is ready, dilute it with 50% water or you will find the vinegar scent overwhelming. I find that this sanitizer is very herby smelling, thyme is intense. To combat this strong scent, I like to add other essential oils such as rosemary and basil. They work with thyme and also have strong scents so the medicinal smell of thyme is toned down a bit. Other cleaning products try to cover it up using essential oils that clash with thyme rather than are complementary.
This spray is great for kitchen counters, toilet seats, door handles, and light switches.