Cornerstone 5 Plus Herbicide is a non-selective herbicide, so it's applied when weeds are actively growing. Depending on how difficult/established the weeds are, you can use it at a rate of 0.6 oz to 13 oz per gallon of water.
Cornerstone has a screw off cap. It may take a bit more strength to unscrew the carp if it was overtightened.
Cornerstone 5 Plus Herbicide is a non selective product meaning it will kill whatever it is sprayed on, so no we would not use this product on the lawn unless you plan to reseed those areas.
Cornerstone 5 Plus Herbicide rates vary depending on the target pest and growth level. Complete information is on the product label.