Here's a recent trip to a very wet Watkins Glen. Shows a different way to heel-toe. I also do this on regular street driving, not often but sometimes. I just needed to blip the throttle very slightly and this gives better control over the blip. I don't particularly like braking with touching half of the brake pedal on the track so I do most of my braking on the full pedal and then slowly slide my foot over the brake pedal to the right (while still finishing the braking) and get it ready to do the blip.
Hope this paints a clearer picture.