I am going to have my existing lawn killed and the company I hired is using a product called Razr - I might have the spelling wrong. I can't find anything on the web about this product, maybe because I don't know how to spell it. Anyway, what I am looking for is how effective it is, how long it takes to work and if it has any residual impact on the soil. The company answered these questions for me, but I always like to do my own research to make sure I am getting the correct product. Thanks!