People use a 'dropper' to get it right down into the lace, but really your issue is how long you leave it to activate before you detach, not how you apply the lace release.

When its fully done its job, the system should practically slide off your head of its own accord!

You shouldn't then get any hairs coming through the wrong side.
Also, when you rinse the hair, always hold it under the water with the base side facing upwards.