salu = healthy (salu for salman khan is very healthy)... insalubrious = not friend of salu... not healthy
compare it to 'Saloon' which is an unhealthy place.
insALUbrious - rememeber alu (potato).. eating aloo everyday is not good for health
using Saulab Sauchalya(public toilet) is not healthy.. hope u get it !!