I recently started using World's Best Cat Litter and I'm pretty happy with it so far, but I just noticed they make an "Extra Strength" formula as well. I live in an apartment and could use as much odor control as possible! The thing is, my cat doesn't like heavily scented litter. The website says it contains "a plant derived ingredient" to control odor, and that it has no "perfume"...but does the plant derived ingredient have a scent (like an essential oil)? Anyone know?