So glad to see you post something. I was afraid that you might be under the weather or worse. Several here including me use Greendoctor's walking boom. I can right to to concrete and never get anything on it by tilting the boom away from the surface and moving backward to an upright position all in the same movement. FEature is only 2oz/K and applying mix containing it at 3 gallon per K, it is fairly diluted.
Again glad to see you post even though it seems that sometimes it is better to let rocks be rocks.
We all are merely gleaners from the masters who were here before us.