Hi Marc, ok mate let me try and make it easier to interpret. In the first pic you use what you see is the result of 'thinning' back the scrub coat overall and the flesh you see, (which you call the base coat) is a single application of a flesh mix. I think it is my poor explanation that has you a little confused here so, I will try to word it better now, I applied the flesh tone in the same way as the scrub coat and thinned it back with the smaller make-up brush. What will help is to make your flesh tone darker than normal to allow for the thinning out. I hope that helps Marc and sorry if I did not make it clear the first time around.
To clean the make-up brushes I use ordinary white spirit when I have finished but, keep in mind, you should not do this whilst working with them as they take time to dry. Remember to keep wiping them out on a paper towel or, ideally, a piece of cotton cloth while you are using them to thin the paint back. Please ask as many questions as you like because it takes a while to get comfortable with any new technique.
Cheers
Ron