Just machine polish them.
You will find often you don't need to wetsand and you should avoid this unless you absolutely need to.
Any PROPER car polish compound eg Scholl, Menzerna etc by machine will be fine.. a mediumy-hard pard on a dual action or rotary polisher. Then be sure to wax them again afterwards as it's the UV rays that fade them.
A machine on its own won't get rid of all the damage.
Tried it, doesn't work, unless you have a day free to burn out your polisher...
well these are my headlights now, not bad for 7 years old and 74k miles using my method, and having the job done in around 30 minutes a side.They are 95% perfect now.
Whilst i was at it, using Wet n dry 3000 and warm soapy water, got rid of all of my minor road rash which comes par of the course with our Mk5's,i wet sanded the bottom 4 inchs of the bonnet that was peppered in touch up marks.
All lenses have been Polished/wax or Sealed after. The front now looks much fresher.
not disputing your methods Jay, but i fail to see how using just a cutting compound will remove all lense damage.
As per this thread, I used far less aggressive wet n dry
http://www.mk5golfgti.co.uk/forum/index.php/topic,26433.0.html