Not sure this is the best way generally but this is the way how I do it and what is best for me:
First of all I enter the right/left combination as early as possible, I go fully over the curbs on the right, but usually only the left wheels will go over the left curbs (up to here everything is full throttle of course, this should work with pretty much any car). My goal is to be in a straight line as soon as possible after the right/left so I can can concentrate on when to steer to the left again, as this is by far the most tricky part.
The upcoming walls do have an angle at the end, and what you want to do is drive parallel to the wall at the end where it is angled, because if you are in this angle and if you are close to the wall then there is a small path to push through there.
So the point is to start steering towards the wall rather early (before the curbs on the right end), but only a little, so you line yourself up to be parallel to the wall on the left where it ends.
So it is less of steering left and right, but rather steering a bit to the left, lining yourself up for the end of the wall, to push through in pretty much a straight line, and then as soon as you have cleared the wall (at a close distance) start steering to the right (only if you see you have enough room for the wall on the right of course...).
If you follow this line then you also only have to steer to the right a bit at the exit and run much less danger of hitting the wall to the left after the exit.
What you absolutely do not want to do is start steering to the left on the small straight too late - if you start steering to the left after the curbs have ended you are definitely too late - you won't have a problem with hitting the corner on the left, but you have to greatly reduce speed to not hit the corner on the right and the wall to the left after the exist.
Regarding when to lift the throttle: it is possible to go through this flat out with the M6, I have done it a couple of times in qualifying, but more often than not I crash. So this is very risky in my opinion. So the much safer way is to lift the throttle, I'd say around where the curbs are on the small straight, this will give you a larger margin for error, so you can start steering to the left a bit later (but not much!), and allows you to clear the two corners at a safer distance without running the risk of hitting the wall at the exit.
Someone above said to see it as one large left turn - I don't see it that way, but i guess depending on your style this is what might work for some/many. I find it easier to line myself up for the left/right if I am approaching this in a straight line.
But the main point in my opinion is to think of this more of lining yourself up to push through in pretty much a straight line, rather than a turn to the left and one to the right.
In the end it is a bit similar to the double chicane on Yamagiwa at the bottom, where you also have to try to push through in pretty much a straight line. Of course the risk at the Dragon Trail bus stop is much higher though