Buying a cleaning kit or deliberately overfilling on water prior to taking the test is a very bad idea. Most of the places test for common adulterants, and if the specific gravity of your urine is too low (from drinking too much water) you will fail the test.
I read and absorb material much, much faster than most people (even physicists). That is my strength. My weakness is my difficulty in concentrating on any one thing for very long.