i first went wfp 9 years ago but only lasted a week and sent it back saying it would never catch on, the customers where ready to lynch me for leaving their windows wet , but due tyo Health and safety we had to give it another go 18 months since, the first clean of work was a nightmare but customers can now see it does work and are more reseptive to it , unlike traditional you do get the odd job that dries not perfect on occasions and you rack your brain wondering what went wrong but this only happens occasionally and less and less when you know what to look for ie vents , hot sun on glass and dirty brush from first cleans.