The most accurate method I understand for cross talk is using a digital volt meter and measuring the output of a 1KHz tone. This method is difficult as you really need a filter so you are only measuring in the 1KHz range, this way the measurement is not bouncing all over the place.
This is why I use the Fozgometer, since it has that filter built in, the analog meter is very still easy to read. Measuring for cross talk is to play a 1KHz tone in R channel and measure the L channel, then reverse. You can use the Foz to do this, just disconnect the R cable and the meter will drop to a very low level since it is measuring the info in the L channel. Note the needle position, then adjust based on other reading.
When I do this, the meter results are similar to exact. 1) L and R readings are within half a hash mark. 2) Channel balance the needle is dead on ZERO with the mono 1KHz tone.
The real results are the soundstage is wall to wall, bass is deep and articulate and very importantly surface noise is greatly reduced and with new records almost gone.