prepare the soil around perimeter with plastic lining (in trench) and course sand.
Use pidgins termite insecticide and pump through ststem using pump spray.
Sorry for digging up an old post, i havnt been on here for a while and was reading through a few posts and came across your "DIY" Re-ticulation system.
In my opinion i would avoid from using a course sand as sand is very hydrophobic and will not allow the chemical to evenly distribute. Also there is no reason to install a plastic lining.
You would be far better off to use a nice sandy-loam type soil.
You could do an experiment to see for yourself. Place one pile of sand and one pile of a sandy-loam next to each other and pour water on the top of them. On the sand the water will simply run off, where with the sandy-loam will absorb the water. The chemical binds to soil particles, so you want it to remain where it is being applied.