I am currently using a synthetic grass toilet for my senior dog on the balcony of our apartment however, coming into the warmer months I was worried about being able to leave our sliding door open to let the breeze in due to the smell. After trying a few products on the market Petlab has worked the best for us. The others left a sickly perfume mixed with wee smell that was only a temporary fix (we were having to clean the area daily). Using petlab we notice the smell is completely removed and lasts for a couple of weeks. By having rotating grass mats and using the two-step system from Petlab on the one not in use we have resolved the issues we were having! Highly recommend.