So you slip the clutch to keep the rev's up / scrubb speed, instead of using the brakes, while keeping the throttle planted?I will keep the gas mashed and modulate my brakes to scrub speed, usually on sweepers and sometimes on slaloms. But I have never used the clutch. I would think it would upset the balance too much. I must say you are the first person to ever mention doing it that I have seen. As long as it works for you. I don't think I will try it soon.
It's kind of weird; I don't left brake my care except in competition, I will LFB my work truck and my wifes car some times, but they are both slushboxes. But when I get in the car to go run at an autox, as soon as I shift into second, my left foot moves over to the brake. I don't even think about it, it just happens automatically. I just started LFB last year. If I may make a suggestion; try LFB on the street before you do it at an autox, especially if you can find an auto to drive, it makes it much easier. I started doing it the first time I drove a friends Miata. I had seen enough people spin his car, and new it was set up to rotate really well, so I just went for it. I used the brakes WAY to much but I never spun it. It is a handy tool to have. Plus i think there was a side bet on how many times / where I would spin his car.