Toyota Repair: 95 Camry Problem with oders, drain tube, oders

Question
I recently purchased a 95 Camry DX 4 Dr. Sedan.  There is a terrible oder which gets worse if you put on AC.  The smell is like dog poop.  I have looked everywhere for advice, was told I needed to get a A/C evaporator treatment to put on evaporator.  I am female and no absolutely nothing about this.  I have called several automotive stores and they say they never heard of this.  Any help or advice you can provide is greatly appreciated.

Answer
Toyota dealer has this, A/C REFRESHER ,here the labor is a 1/2 hr the kit comes in two cans one is a foam that has a hose on it , there is a drain tube for the the evap, clear water drips from this, we put it on the rack and eng off we shake the can up and stick the the evap with the hose off the foam can that has a cone tip, after all is injected into the evap, we wait, after 1min or 2 it drains back out, the other can we take eng on A/C on fresh air we spray this can in the vent under the wipers, then on recirculate we spray under the pass side floor board where the evap takes in air, then all around the inside of car, then we leave the rest in the car. If you here the fan making a funny noise before doing this you may have a dead rat in the blower this is another 1/2 hr to remove and clean and gag and gag somemore, it's worth more, the rat cleaning that is. Hope this is what your looking for.