It works really good by machine , but I guess you're doing it by hand ?
You want to do it in lines , not circles and wipe the stage #1 cleaner off with a 50/50 mix of 90% alchohol and water and a damp microfiber towel .
Then stage #2 same way , but only wipe off the excess with a dry MF towel ( different one ) or some light sprays of quick detailer to help remove it .
Only do one panel at a time before removing it though or it'll dry . Half panels if in the sun .
Step 3 apply with a foam wax applicator and remove with a clean dry MF , and use QD if needed .
How much time spent is only and issue if youre using a machine , in that case keep it moving .
By hand as long as you want