Note that the BIOS may regulate to a given temperature -- this will tend to hide your cleaning process. To find out for sure, you need to stress the GPU and CPU with a reasonably strenuous task.
If you see the temperature climbing over the setpoint, you know you need to fix something (clean the fan, do the goop better, replace a heat pipe, etc.).
My laptop normally sits around 60C, varying between 50C or below when idle and up to 70C when fully cranking on a warm day. I've seen it go over 80C before (it shuts down if the GPU goes over 100C
), which required replacing the heatsink assembly (bad heat pipe).
SpeedFan is recommended for monitoring temperatures, fans, etc.
Tim