UB, i have had yotes 15 yards downwind.
I use homemade colloidal silver,with no sent,just silver and distilled water.
Here is primos brands
http://www.primos.com/silverxp/Also i wear a bees keepers net sprayed with the silver.
To catch those skin cells.
here is my silver maker setup.a plastic mayonaise jar.
2 holes a inch apart in the top for the silver rods to go down into the distilled water,
how to make the silver.
a dc power source is needed,9volt or 12.or bigger.
like a cordless drill charger,etc.
Cut the plug off put 2 wire clips on the ends.
This takes about 10 minutes.
Get 2 silver bars at a coin shop 999 silver
they will cost you 6 to 10 dollars,and last a lifetime or you can get .9999 silver here 1 foot for 10 dollars.
http://www.ccsilver.com/silver/superfines.html#four This will also last a long time.
all parts will cost you about 20 dollars new.
but many have the parts needed laying around the house.
After putting it together,it only costs the price of a jug of distilled water.70 cents.
i have about 150 gallons on mine and they are nearly as i bought them.
Here is the instructions.
http://www.lightawtcher.com/makingcolloidalsilver/make_silver_generator3.htm