We agree that spending an hour removing your makeup is excessive.
While you should try your best to remove all your makeup, if there are tiny unnoticeable remnants left, they would not be considered a chatzitzah.
We recommend spending 10-15 minutes removing your makeup, doing the best you can, and that's it. Don't worry if there are small traces of makeup left. You can try experimenting with different types of makeup remover to see if you can find a more effective remover. Another suggestion is not to put on any makeup (or at least minimal makeup) the day you plan on immersing to minimize the difficulty of removing your makeup during your preparations. With time and practice, you may be able to reduce the amount of time spent on removing your makeup to less than 10-15 minutes.
Please feel free to get back to us with any further questions.
B'Hatzlacha!