I got a tin of this stuff a while ago from my local dealer, but it didnt have a tube attached, after deciphering the german (!) instructions on the can, i figured out you had to put the AC on full blast, recirculating, press the top of the can down and put it in the passenger footwell, then close all the doors. The whole can gets discharged into the car over about 5 minutes, then you leave the AC on for another 5 for it to work through the system. It left the car smelling of apples for a few days
)) but the dodgy smell came back quite quickly. Do you have a part number for the stuff you got? The spray things sounds miles better, especially sprayed straight onto the evaporator.
Cheers
Crad