Unfortunately the
tree huggers took away the best thing in the arsenal against ticks, when they pushed for the ban on organophosphates such as Diazinon and Dursban. I think about the best thing that you could do is contact one of your local lawn care companies and ask if they do tick spraying. Treating for ticks is very difficult for the homeowner to do effectively. In most cases you will just wind up taking out a bunch of good insects and not really get the control you want on your ticks.
The one bad point about DEET is the fact that it can soften plastics such as watch and cell phone faces, so it would be a good idea to remove them when applying.
Using tick sprays like DEET or Avon's Skin So Soft are great when you are in the ticks area, but I do believe if you have a problem with ticks you should spray because they so easily invade our area. They are carried inside our homes on cats, dogs, and mice, and can still get us when we are not protected.
As far as "chemicals" go DEET is NOT an insecticide. It works the same way as SSS does. It is actually just a cover scent which blocks the scent of carbon dioxcide as it exudes from our bodies. The ticks pick up on this scent and fall off the brush on to us. This is also the same scent that skeeters home in on.
Both the CDC and the AMA have both stated DEET is safe for use on children over the age of 2 and recommend its use if you are going to be in areas where ticks or skeeters are a problem.
Deet has received a really bad name in the past by people who knew nothing of which they were talking about, and it is really too bad since it is so effective.