I tried that stuff, and it is amazing! It works even better that my gas mileage booster, and ALMOST as good as my cellphone antenna booster. The only area that it does not measure up is when comparing it to how well my magnetic bracelet works....
Reminds me of back when I was working at RatShack, and we sent a new hire down to another store to pick up a case of antenna sealer. "The type you put on telescoping antennas so the signal doesn't escape through the breaks between segments".
No spray bottles for me...I'm rigging up a fully automated nozzle system (like sprinklers) driven by an Ocelot and SECU16 outputs. I have it all zoned so that only the area where the data rate drops too low gets a dusting.
Would it make sense to run "soaker hoses" on the ceiling above the routes your signal takes? This would ensure even distribution along the entire length - eliminating slow spots.
It may require more spraying, but maybe using this approach would allow you to guide the signals, even turning corners. If you can get data to follow a path around corners and along hallways, then you eliminate the problems going through walls and floors.