Cleaned Air Con - Stinks again?

[IainMW]

Ran a can of Comma Air conditioning cleaner through the system 3 weeks ago, which got rid of the nasty niff's. Got in the car this morning and it stinks again?
The pollen filter was changed just over a month a go when the car was serviced, so it's not that.

When I picked the car up from the garage on Wednesday, I was looking at a can of Renault Air Con treatment (£17 ) but it had a long plastic tube attached to the spray nozzle. If I remember correctly the instuctions said to spray the contents of the can onto the evaporator through the inspection access, and then run the fans on slow for 5-10 minutes with the AC switched on.

Now, I seem to remember a comment by WebCode some time ago that the only air con treatment to use was one that runs through the system with the fans on full and air recirculation switched on?
Does anybody know if the pollen filter is bypassed when air recirculation is switch on? If not then the air con treatment is going to be absorbed by the filter and not reach the evaporator, thus not doing the job it meant to do, resulting in the nasty niff's returning sooner than they should?

Am I waffling hear?

[WebCode]

Remove the old pollen filter, Set the A/C at Recirculation and set the "forte" type treatment off..
This will kill the bacteria on the evaporator, However it is a temp measure and must be repeated regularly to ensure the bacteria doesn't return. Especially if the A/C is not used regularly.