Backtrolling provides good boat control, still, using ropes and two helpers on bow and stern is best way to apply.
Regarding application - here's my application method: Throw AT water 2 OZ product A, then 2 OZ product B, covers 11 sq ft area. You can also toss few OZ of bentonite on top of A/B to help it sink. Move linearly to next 3.5x3.5 area and treat, repeat. Just like painting...cover entire area thoroughly. Any questions let me know can cover a lot more ground over the phone.
Many men go fishing all of their lives without knowing that it is not fish they are after. ~ Henry David Thoreau