Menzerna does work well, but since it's water based, it has a learning curve for those not used to polishes like that. Mez does not have oils to my knowledge, so that's why it's difficult to remove. Oils make it easy to remove polish residue and make the finish look glossy. That's why it has to be worked until almost dry. It's OK, but for faster results, I'd try the following.
If you have a fair amount of swirls, you can use DACP and I follow with 3M P-III MG then Mez/FP or Megs #3 as a final glaze to really bring up the shine. I finish with a grey finish pad so all "cutting" is done by the product, not the pad once everything is out. There are so many finish glazes and it all depends if you are going to wax or sealant the finish. If waxing, stay with the 3M line and finish with 3M P-III FG, which is a finish glaze that has carnuba in it. Looks very nice after polished out with a finish pad! See what others use. If you go to the sealants, you need to remove oils after polishing.
Just don't wipe the Mez too hard, or you'll put scratches back on! Just use a damp MF towel, or water spray to assist.
Here's what my SC430 looks like after all the hard work:
Deanski SC430
This was done mostly with the 3M PIII-MG and a white pad as it was not too bad in the swirl department. Just removed all the ones the "Swirl Mark and Scratch Application Department" did at the dealership when I took delivery. Next time, I'll request to leave it alone!
Once you get the hang of the PC, you'll be fine! Don't rush! Too many people new to the PC think this will be quick, which it can be once more experienced, but first time usage, schedule enough uninterrupted time so you can get the feel of it, how it works/reacts with polishes and how it reacts to your finish. Best way if you have access to a garage, get a halogen work light and shine it on the finish. Notice all the defects? Then start with the PC, wipe and get the light again. Defects starting to go away? Great, keep going and keep checking. This way, you get more confident with it and see how well it's working. If nothing improves, time for more agressive product and or pad. Just check again and you'll do well!
Have a nice day!
Regards,
Deanski