Someone miscalculated the rate and applied a 10x rate of B-Nine(10,000ppm) to rooted ctgs. I want to apply Fascination but I don't know how many ppms I should apply (we normally use around 10)

My suggestion is to be a little conservative and make sure you do not get too much stretch. You have time to get size and doing this with B-Nine is not as bad a situation as with stronger products. In Florida, where I use a spray volume of 3 gts/100 ft2, I would use about 3 ppm and repeat 7-10 days later if cuttings are not growing. Keep some untreated cuttings so you can see the Fascination effect. When cuttings start growing, you will probably see a lot of variation and may need to hit only some of them a second (or third) time. Cuttings with terminal covered by a leaf will not respond as well as ones where the terminal is hit by the spray. Fascination sprays work better the longer the solution stays wet on the plant. So, in your dryer climate you may need the higher rates that you have used before. Good luck! Jim