Using BSGS/kangaroo, you could check Tk/s (trillion keys, thousands of trillion keys per second), GPU is much faster than CPU in this case.

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The script posted on previous page won't work, it's just dividing one key, in order to successfully divide a key, you'd need to make sure that the key is +n and also even, since we don't know it's odd or even, we'd have to assume our original key is odd, then we'd add 1 G to it, then divide both, we will then treat the results as same as our starting keys, adding 1 G to each one and dividing all, keeping all the keys, how many times we divided, how many G we added, they are all important.

But note that when you divide a key, the result could be -n version, adding 1 G and dividing that -n key will get you no where, so you'd need  to do all the operations on both -n and +n keys. This should take less than a second if you have the proper algorithm implemented with the correct tool!