Trying something new today, this is the 4th cleaning I've done for the AC system due to smells...
Attempt 1: Interdynamics AC Vent cleaner ($10) + new filters - Worked for about 3 months but left a bit of a pungent/cheap cleaning agent smell, has a nice little spray nozzle tube to help spray into the fins a little
Attempt 2: Klima cleaner ($18)+ new filters - Highly recommended by people, comes with a strange 360 deg extension tube, worked for about 2 months for me, the spray nozzle doesn't direct foam right into the fins so the coverage was a little suspect. Left the car smelling quite clean and scentless.
Attempt 3: Microban anti viral spray ($6) + new filters - Worked for like 2 days... doesn't seem to get deep enough into the fins even though I sprayed with the fan on, do not recommend!
Attempt 4 today: Unloaded a giant can of Frost King AC cleaner ($6.5), used a coat hanger to direct the spray nozzle from a can of Kool-it ($15). Frost King is 19oz, vs 6oz of Kool it. I haven't used the Kool it yet, saving it for next time the car stinks. The spray nozzle setup directs a fairly powerful jet of foam right into the coils. I moved the coat hanger around to jet the foam to the entire surface of the coils. After about 1/2 a can the foam was building up and started over flowing out of the filter access hole. I waited 15 mins and sprayed the rest of the can into the coils again, then waited 30 mins for the foam to dissipate and liquidfy. Everything drained out. Frost King can doesn't come with a spray nozzle extension, so it wouldn't be very effective for the Tesla if you don't already have one from a different product like Kool-it.
So far the car smells very clean with no strange cleaner scent. In my case I'm 100% certain the sour smell does not come from the filters. I'll update the thread when it starts to stink again!