in my experience,
Heat sinks reduce the likelihood of being scanned, not the avoidance of scans.
Also helping is the type of station that you are flying into and the volume of Police flying around.
The most reliable method I found for entering a station whilst carrying illegal goods was to line up with the slot from more than 5kms out, ask for docking permission and once received, drop to silent running, full acceleration and print for the slot.
If your temperature gets too high, drop a heat sink.
Once inside a slot, full brake and remove silent running. You won't get scanned once inside the slot so you only need to breach the threshold and then you can relax.
You can do this in all ship types however some are better at getting through the slots compared to others.
The Uber brave out there could do this in a type 9 and make an absolute fortune for example.... or they could end up wedged in the slot and lose the fortune...