Used a torch for ages on commercial. 
Tried in on domestic last year to clean between 3.30 and 5pm. 
First house first window I annoyed a cat. Second window I must have blinded it. He then went crazy in the house and decided to rip down every blind in the house. I am still paying for the blinds today. Some could be repaired others destroyed. 
I used a £50 bike led headlight. It must have been blinding lol.