Good that you are doing it again as I know you got a well established team
Break down the price a bit more
So 200% for every customer who stays for a 2nd clean as a one off would be someone who says regular on the door then cancels so those are free?
0.00% for a customer who changes there mind or who pays and cancels or who pays then pretends they want a regular service until next time when they scream no no no!!
I recon £10 per paying customer is the way to go no guarantees cos what will happen if you are hit with a 50% cancelation after the first clean which is getting very common these days by the way I'm sure you are aware of the problems